Disconnect and reconnect — go to Campaign Settings → Integrations and API → Rewards tab, disconnect Tremendous, then reconnect. This forces a re-sync of your campaigns.
Wait a moment — recently created campaigns can take a short time to sync between Tremendous and Referral Factory.
Verify the campaign exists in Tremendous — log into Tremendous and confirm the campaign was saved correctly.
Check which account is connected — if you have more than one Tremendous account, you may be connected to the wrong one. Log out of all Tremendous accounts, log into the correct one, and reconnect.