GOOGLE HAS REMOVED MANIFEST V2 EXTENSIONS FROM THE CHROME WEB STORE, INCLUDING UBLOCK ORIGIN

Summary from the TLDR newsletter

All remaining Manifest V2 extensions have been removed from the Chrome Web Store. Manifest V2 extensions installed on Chrome 138 or earlier will remain installed. However, they will be unable to receive any updates and cannot be reinstalled from the Chrome Web Store once removed from Chrome. Users will no longer be able to find or install Manifest V2 extensions through the Chrome Web Store even if the Chromium-based browser they use continues to support Manifest V2.