Button to open xbox app to view game in "Is It On Game Pass" won't work - Steam unable to handle msxbox:// protocol to open Xbox app

[ShepoPL]

Extension name

Is It On Game Pass

Chrome Web Store URL

https://chromewebstore.google.com/detail/is-it-on-game-pass/lcobepkldcbbjfnpjnonocmlifjdlcdh

Extension version, can be found in the extension's details page (if known)

1.1.7

Problem type

• Won't install / download fails
• Installs but doesn't run
• Action button missing or not clickable
• Options page doesn't open or is broken
• Background service worker errors
• Feature(s) not working as expected
• Crashes / errors shown in console
• Other

Describe the issue

Steam fails to open Xbox app when clicking "Open in Xbox App" button

"The website under msxbox://game/?productId=BQVQTL3PCH05 may be temporarily unavailable or may have permanently moved to a new web address."

Confirmation

• I tested with the latest Extendium version
• The extension works in Google Chrome (or another Chromium browser)

Extendium Plugin Version

v1.1.1

Millennium Version

v2.34.0

Operating System

Windows

Steps To Reproduce

1. Install Is It On Game Pass via Extensions Manager
2. Go to any game page that's marked as available on game pass.
3. Click"Open in Xbox App" button
4. ERR_UNKNOWN_URL_SCHEME

Logs / Console output

No response

Other installed extensions (optional)

Augmented Steam - 4.6.2
Link in Current Tab - 1.0.12
SteamDB - 4.32

Troubleshooting tried

• Restarted Steam
• Reinstalled this extension from the Chrome Web Store URL
• Switched to Default skin/theme
• Removed other extensions to rule out conflicts

[ShepoPL]

Self-made fix:

Changed and added additional lines in extendium.extensions\is-it-on-game-pass\scripts\content-script.js

/**
   * Detect if running inside the Steam client's embedded browser (via Millennium/Extendium or native Steam)
   * @returns {boolean} True if in Steam client browser environment
   */
  isSteamClientBrowser() {
    if (typeof window.SteamClient !== 'undefined' && window.SteamClient !== null) {
      return true;
    }
   const ua = (navigator.userAgent || '').toLowerCase();
    return ua.includes('steam') || ua.includes('valve');
  }

      const isSteam = this.isSteamClientBrowser();
      const useWebLink = isMobile || isLinux || isSteam;

Took advantage of existing function to change button's redirect if specified environment detected:

// Set appropriate URL and title based on device type
      if (useWebLink) {
        xboxButton.href = `https://www.microsoft.com/store/productId/${options.msStoreId}`;
        xboxButton.title = 'View in Microsoft Store';
        xboxButton.target = '_blank';
      } else {
        xboxButton.href = `msxbox://game/?productId=${options.msStoreId}`;
        xboxButton.title = 'Open in Xbox App';
      }

After saving the edit, button successfully redirects to the game's xbox page in steam browser.