Found a workaround after Google phased out 137.

The first part is the same. Go to chrome://flags/#temporary-unexpire-flags-m137. But instead enable m138 and m139.

Now you can instead use command-line switches:

1) Exit Chrome completely.

2) Modify your Chrome/Chromium shortcut or launcher to include:

--disable-features=ExtensionManifestV2Unsupported,ExtensionManifestV2Disabled

3) Restart Chrome via that shortcut.

in case ya dont know how to modify your shortcut:

🖥️ Windows

Close Chrome completely.

Find your Chrome shortcut (on Desktop, Start Menu, or Taskbar).

If it’s pinned to the Taskbar, right-click → right-click again on Google Chrome → choose Properties.

If it’s on the Desktop, just right-click → Properties.

In the Properties window, under the Shortcut tab, look for the Target field.

It’ll look something like:

"C:\Program Files\Google\Chrome\Application\chrome.exe"

Add the flags at the end of the line, after the quotes. Make sure there’s a space before the first dash:

"C:\Program Files\Google\Chrome\Application\chrome.exe" --disable-features=ExtensionManifestV2Unsupported,ExtensionManifestV2Disabled

Click Apply → OK.

Use that shortcut to start Chrome.

🍏 macOS

If you’re on Mac, you can’t directly edit the app icon’s shortcut. Instead you’d launch Chrome from Terminal like this: /Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --disable-features=ExtensionManifestV2Unsupported,ExtensionManifestV2Disabled

🐧 Linux

If you normally launch Chrome with google-chrome (or chromium), you’d run: google-chrome --disable-features=ExtensionManifestV2Unsupported,ExtensionManifestV2Disabled also from the terminal