Connect your identity provider
Everything lives on one screen: Settings → Security, under “Single Sign-On” (saving needssettings update).
Verifying a domain
Each added domain starts Pending with a unique TXT challenge shown on the card:
Publish the record at your DNS host, click “Verify”, and on a match the domain flips to Verified. Verification is one-time; the TXT record can be deleted afterwards. A Pending domain has no effect anywhere, so adding one is always safe.