Check YouTube Music like songs status in your playlists.

youtube-music-check.js

let numAll = 0;
let numFine = 0;
let numError = 0;
let List = [];
let ErrorList = [];

document
  .querySelectorAll(
    "ytmusic-playlist-shelf-renderer > div > ytmusic-responsive-list-item-renderer"
  )
  .forEach((element) => {
    const song = element.querySelector(
      "ytmusic-like-button-renderer[like-status='LIKE']"
    );

    if (!song) {
      ErrorList.push(
        element.querySelector(
          ".title.style-scope.ytmusic-responsive-list-item-renderer"
        ).title
      );
      numError += 1;
    } else {
      numFine += 1;
    }

    List.push(
      element.querySelector(
        ".title.style-scope.ytmusic-responsive-list-item-renderer"
      ).title
    );
    numAll += 1;
  });

console.log("All :", numAll, "\nFine:", numFine, "\nErr :", numError);
console.log("Songs:", List);
console.log("Error Songs:", ErrorList);

youtube-music-like.js

document
  .querySelectorAll(
    "ytmusic-playlist-shelf-renderer tp-yt-paper-icon-button[class~='like'][aria-pressed='false']"
  )
  .forEach((element, i) => {
    setTimeout(() => {
      element.click();
    }, 1000 * i);
  });

youtube-music-unlike.js

document
  .querySelectorAll(
    "ytmusic-playlist-shelf-renderer tp-yt-paper-icon-button[class~='like'][aria-pressed='true']"
  )
  .forEach((element, i) => {
    setTimeout(() => {
      element.click();
    }, 1000 * i);
  });