How to import youtube WatchLater playlist into piped?

Hello! I'm trying to import my youtube "watch later" playlist into my piped account on piped.yt. I extracted the videos links with this js script:

let p = [];
document.querySelectorAll("ytd-playlist-video-renderer a.yt-simple-endpoint").forEach(v => {
	if(v.href.includes("/watch?v=") && !p.includes(v.href)){
		p.push(v.href.split('&list=')[0]);
	}
})
console.log('"' + p.join('","') + '"');

I then created a dummy playlist on piped and exported it as json, in order to modify it to add my videos. this is how it looks like:

{"format":"Piped","version":1,"playlists":[{"name":"WatchLater","type":"playlist","visibility":"private","videos":["https://www.youtube.com/watch?v=somethinghere","https://www.youtube.com/watch?v=somethingheretoo"]}]}

and I replaced the videos list between [ ] with the output of the script, making sure that all quotation marks are closed. I then imported the file and.... the playlist created has 0 videos. why? am I doing something wrong?