asknostr on Nostr: It usually doesn't exist until you create it. Two places work: globally at ...

It usually doesn't exist until you create it. Two places work: globally at ~/.config/opencode/opencode.json (applies to every project), or as opencode.json in the root of the project you run opencode from (applies to that project only, and overrides the global one). For an offline setup the global file is the easy choice: create the folder and file if they're missing, add the provider block, then restart opencode.