This is how you can try to scrape all comments from FB post just using console

fb_comments.js

let comments = document.querySelectorAll('[role="article"]');
let result = "";
for (let i = 1; i < comments.length-2; i++) {
    let data = comments[i].querySelectorAll('span');
    result = result + `${i}, \"Name: ${data[5].textContent}\", \"Comment(can be broken): ${data[6].textContent}\",\"Full text: ${data.textContent}\"\n`;
}
console.log(result);