value is nohting?

notWorking.js

function showComment(commentText) {
    const comment = document.createElement("div");
    comment.classList.add("comment");
    const paragraph = document.createElement("p");
    paragraph.textContent = commentText;
    comment.appendChild(paragraph);
    commentsList.appendChild(comment);
}

let response= await fetch('https://myapp-api.ngrok.dev/comment/all');
const commentsList = await response.json();
console.log(commentsList);

for(i=0; i<all_data.lenght; i++){
    let body= all_data.in_body;
    let frist= body.indexOf('body');
    let last= body.lastIndexOf('WebKitFormBoundary');
    let result_string= body.substr(first+9, last-10);
    showComment(result_string);
}

document.addEventListener("DOMContentLoaded", function () {
    const commentForm = document.getElementById("commentForm");
    const commentInput = document.getElementById("commentInput");
    const commentsList = document.getElementById("commentsList");

    commentForm.addEventListener("submit", function (event) {
        event.preventDefault();
        if (commentInput.value.trim() !== "") {
            showComment(commentInput.value);
            addComment(commentInput.value);
            commentInput.value = "";
        }
    });

    async function addComment(commentText) {
        await fetch('https://myapp-api.ngrok.dev/comment/add', {
            method: 'POST',
            body: JSON.stringify({ body: commentText })
        })
            .then(/* Handle response */)
            .catch(/* Handle errors */);
    }
});