dear authorized, brave I can’t add metamask extension as add-on or extension in the latest current version, do you have any work on it? thanks for your interest.
Which Brave version that you use? Menu > About Brave.
If you’re on 0.58.x, you can install MetaMask from Chrome Web Store. Just click the “Add to” button. https://support.brave.com/hc/en-us/articles/360017909112-How-can-I-add-extensions-to-Brave-