How to use it ?

Update to fix recent changes:

// ==UserScript==
// @name        vids.io download helper
// @match       https://vids.io/videos/*
// @match       https://*.vids.io/videos/*
// @grant       none
// @version     1.0
// ==/UserScript==

//this userscript will do most of the work when you want to dl a video from vids.io
//all you have to do is download the m3u8 data through something like ffmpeg (youtube-dl didn't work for me), e.g. using the command shown below the DL button

async function main(){
  const videoIframe = document.querySelector(".sproutvideo-player");

  if(!videoIframe) { return }

  const videoIframeHtml = await (await fetch(videoIframe.src)).text();

  const videoIframeDoc = new DOMParser().parseFromString(videoIframeHtml, "text/html");

  const videoDataElement = [...videoIframeDoc.head.childNodes].find(e => e.innerText?.startsWith("const videoInfo ="));
  const videoDataBase64 = videoDataElement.innerText.match(/const videoInfo = '([a-zA-Z0-9\+\/\=]+)';/)[1];
  const videoData = JSON.parse(atob(videoDataBase64));

  const indexM3u8 = `https://hls2.videos.sproutvideo.com/${videoData.s3_user_hash}/${videoData.s3_video_hash}/video/index.m3u8?Policy=${videoData.signatures.m["CloudFront-Policy"]}&Signature=${videoData.signatures.m["CloudFront-Signature"]}&Key-Pair-Id=${videoData.signatures.m["CloudFront-Key-Pair-Id"]}&sessionID=${videoData.sessionID}`;

  const qualities = (await (await fetch(indexM3u8)).text()).match(/[0-9]+.m3u8/g);
  const bestQuality = qualities[qualities.length - 1];

  const videoM3u8 = `https://hls2.videos.sproutvideo.com/${videoData.s3_user_hash}/${videoData.s3_video_hash}/video/${bestQuality}?Policy=${videoData.signatures.m["CloudFront-Policy"]}&Signature=${videoData.signatures.m["CloudFront-Signature"]}&Key-Pair-Id=${videoData.signatures.m["CloudFront-Key-Pair-Id"]}&sessionID=${videoData.sessionID}`;
  let videoM3u8Data = (await (await fetch(videoM3u8)).text());
  //replace key with full url
  videoM3u8Data = videoM3u8Data.replace(/URI=\"[0-9]+.key\"/, `URI=\"https://hls2.videos.sproutvideo.com/${videoData.s3_user_hash}/${videoData.s3_video_hash}/video/${bestQuality.replace(".m3u8", ".key")}?Policy=${videoData.signatures.k["CloudFront-Policy"]}&Signature=${videoData.signatures.k["CloudFront-Signature"]}&Key-Pair-Id=${videoData.signatures.k["CloudFront-Key-Pair-Id"]}&sessionID=${videoData.sessionID}\"`);
  //replace .ts files with full url
  videoM3u8Data = videoM3u8Data.replace(/[0-9]+_[0-9]+.ts/g, `https://hls2.videos.sproutvideo.com/${videoData.s3_user_hash}/${videoData.s3_video_hash}/video/$&?Policy=${videoData.signatures.t["CloudFront-Policy"]}&Signature=${videoData.signatures.t["CloudFront-Signature"]}&Key-Pair-Id=${videoData.signatures.t["CloudFront-Key-Pair-Id"]}&sessionID=${videoData.sessionID}`);

  const filename = document.querySelector(".video-title h2").innerText.replace(/[^a-z0-9]/gi, "_");
  const dlElement = document.createElement("a");
  dlElement.href = window.URL.createObjectURL(new Blob([videoM3u8Data], {type: "application/x-mpegURL"}));
  dlElement.download = `${filename}.m3u8`;
  dlElement.innerText = "Click to download";
  dlElement.style = "display: flex;justify-content: center;height: 40px;font-weight: bold;background: #9234f0;width: 200px;color: white;align-items: center;margin: auto;margin-bottom: 20px;";
  document.querySelector(".video-info").appendChild(dlElement);
  const infoElement = document.createElement("div");
  infoElement.style = "display: flex;justify-content: center;";
  const infoTextElement = document.createElement("span");
  infoTextElement.innerHTML = "What to do next:<br><br>" +
    "DL m3u8 using ffmpeg:<br>" +
    `<b style=\"font-weight: bold;\">ffmpeg -protocol_whitelist file,http,https,tcp,tls,crypto -i "${filename}.m3u8" "${filename}.mp4"<b>`;
  infoElement.appendChild(infoTextElement);
  document.querySelector(".video-info").appendChild(infoElement);
}

main();

It worked for a while and now it stopped. Any update?