Use your Grounded Therapy Google account.
Anyone with a @groundedtherapy.org Google account can sign in (new accounts start as viewer). Owners set who can post.
Credentials are stored server-side and never shown again after saving. Saving runs a live login test.
Free. No account yet? Create one at bsky.app, then mint an app password at Settings → App Passwords — never paste the real account password.
Pay-per-use ($0.015/post; $0.20 with a URL). Create an app at developer.x.com, buy API credits, paste the four OAuth 1.0a keys.