Before doing anything, you need to have Safari 14 or above installed.
- Grab and install Better TweetDeck on the App Store.
- Open the app and click "Quit and Open Safari Extensions Preferences..."
- Safari will open and select the Better TweetDeck extension, make sure to enable it (see screenshot)
- Go on https://tweetdeck.twitter.com, click the toolbar icon that the extension adds and allow it to run on all websites. (see screenshot)
- You're done!
Feek free to reach out on Twitter @BetterTDeck if you run into any issues.