Bluesky
Bluesky needs no developer app. Connect with an app password.
Bluesky doesn't use developer apps, so there's nothing to set up under Platform apps. You connect with an app password.
Create an app password
In Bluesky, open Settings → Privacy and security → App passwords (direct link) and click Add App Password. Copy it.
Don't use your normal password. An app password can be removed on its own and can't change your login.
Connect the account
In Bulkit, open Channels → Accounts → Connect account → Bluesky. Enter your
handle (like yourname.bsky.social) and the app password.