If you want to conceal the buttons, consider assigning an id to the list element:

<ul id="options">
    <li>
        <input type="radio" name="answer" id="answer1" class="answer">
        <label for="answer1" class="radio-text" id="choice1"></label>
    </li>
    <li>
        <input type="radio" name="answer" id="answer2" class="answer">
        <label for="answer2" class="radio-text" id="choice2"></label>
    </li>
</ul>

In the updateQuiz function within the else statement, add:

 optionsElement.style.display = "none";

to hide the list from being displayed.

For a reset functionality, introduce a button and additional element ids to control item visibility and user choices:

    <div class="row no-gutters intro-wrapper">
        <div class="col-12 mt-3 my-md-5">
            <div class="col-12 text-center">
                <p>Some title</p>
            </div>
        </div>
        <div class="quiz-container" id="quiz">
            <div class="start-btn-wrapper">
                <a class="start-btn" href="#" id="startQuiz">Start the quiz <span>&#9658;</span></a>
            </div>
            <div class="quiz-header">
                <h2 class="text-center" id="question"></h2>
                <ul id="options">
                    <li>
                        <input type="radio" name="answer" id="answer1" class="answer">
                        <label for="answer1" class="radio-text" id="choice1"></label>
                    </li>
                    <li>
                        <input type="radio" name="answer" id="answer2" class="answer">
                        <label for="answer2" class="radio-text" id="choice2"></label>
                    </li>
                </ul>
            </div>
            <button id="submit" class="btn btn-primary">Submit</button>
            <div>
              <p id = "outcome"></p>
            </div>
            <div>
              <button class="btn btn-primary" id="resetQuiz">Restart</button>
            </div>
        </div>
        <div class="quiz-outcome" id="quizOutcome">
            <div class="set-1">
                  <h2>Some text title1</h2>
                  <p>Some description etc etc</p>
            </div>
            <div class="set-2">
                <h2>Some text title2</h2>
                  <p>Some description etc etc</p>
            </div>
            <div class="set-3">
                <h2>Some text title3</h2>
                  <p>Some description etc etc</p>
            </div>
            <div class="set-4">
                <h2>Some text title4</h2>
                  <p>Some description etc etc</p>
            </div>
            <div class="set-5">
                <h2>Some text title5</h2>
                  <p>Some description etc etc</p>
            </div>
            <div class="set-6">
                <h2>Some text title6</h2>
                  <p>Some description etc etc</p>
            </div>
            <div class="set-7">
                <h2>Some text title7</h2>
                  <p>Some description etc etc</p>
            </div>
            <div class="set-8">
                <h2>Some text title8</h2>
                  <p>Some description etc etc</p>
            </div>
        </div>
    </div>
</div>

const quizData = [
  {
    question: "This is question number 1",
    choices: ["Answer 1-1", "Answer 1-2"],
  },
  {
    question: "This is question number 2",
    choices: ["Answer 2-1", "Answer 2-2"],
  },
  {
    question: "This is question number 3",
    choices: ["Answer 3-1", "Answer 3-2"],
  },
];

function determineOutcome(answers) {
  const outcomes = {
    "Answer 1-1,Answer 2-1,Answer 3-1":
      "Set 1",
    "Answer 1-2,Answer 2-1,Answer 3-1":
      "Set 2",
    "Answer 1-1,Answer 2-2,Answer 3-1":
      "Set 3",
    "Answer 1-2,Answer 2-2,Answer 3-1":
      "Set 4",
    "Answer 1-1,Answer 2-1,Answer 3-2":
      "Set 5",
    "Answer 1-2,Answer 2-1,Answer 3-2":
      "Set 6",
    "Answer 1-1,Answer 2-2,Answer 3-2":
      "Set 7",
    "Answer 1-2,Answer 2-2,Answer 3-2":
      "Set 8",
  };

  const combinationKey = answers.join(",");
  return outcomes[combinationKey] || "Could not determine your outcome.";
}

const questionElement = document.getElementById("question");
const optionsElement = document.getElementById("options");
const answerElements = document.querySelectorAll(".answer");
const radioTextElements = document.querySelectorAll(".radio-text");
const submitButton = document.getElementById("submit");
const startQuizButton = document.getElementById("startQuiz");
const quizBtnWrapper = document.querySelector(".start-btn-wrapper")
const resetButton = document.getElementById("resetQuiz");
const outcomeElement = document.getElementById("outcome");


resetButton.style.display = "none";
outcomeElement.style.display = "none";

// Initialize quiz index and user answers
let quizIndex = -1;
const userAnswers = [];

// Function to update the quiz content
function updateQuiz() {
  quizIndex++;

  if (quizIndex < quizData.length) {
    const currentQuestion = quizData[quizIndex];
    questionElement.textContent = currentQuestion.question;

    currentQuestion.choices.forEach((choice, index) => {
      radioTextElements[index].textContent = choice;
    });

    // Clear radio selections
    answerElements.forEach((answer) => {
      answer.checked = false;
      console.log("is this working1");

    });
  } else {
    optionsElement.style.display = "none";
      outcomeElement.style.display = "initial";
    questionElement.textContent = "Quiz Complete!";
    radioTextElements.forEach((text) => {
      text.textContent = "";
      console.log("is this working2");
    });
    submitButton.style.display = "none";
    console.log("is this working3");
  
    // Determine the outcome and display it 
    const outcome = determineOutcome(userAnswers);
    //const outcomeElement = document.createElement("p");
    outcomeElement.textContent = "Your outcome: " + outcome;
    //document.getElementById("quiz").appendChild(outcomeElement);
    resetButton.style.display = "initial";
  }
}

startQuizButton.addEventListener("click", () => {
  quizBtnWrapper.style.display = "none";
  updateQuiz();
});

submitButton.addEventListener("click", () => {
  const selectedAnswer = Array.from(answerElements).find((answer) => answer.checked);
  if (selectedAnswer) {
    userAnswers.push(selectedAnswer.nextElementSibling.textContent);
    updateQuiz();
  }
});

resetButton.addEventListener("click", () => {
  resetButton.style.display = "none";
  userAnswers.length = 0;
  quizIndex = -1;
  updateQuiz();
  quizOutcome.style.display = "none";
  optionsElement.style.display = "flex";
  submitButton.style.display = "initial";
  outcomeElement.style.display = "none";
});