TIL: HTTP methods are case-sensitive

When making different API calls, for example, using fetch() api, request methods are case-sensitive (all UPPER-CASE) according to RFCs 7230 and 7231

The method token is case-sensitive because it might be used as a gateway to object-based systems with case-sensitive method names.

fetch(<url>, { method: [GET, PATCH, PUT, DELETE, etc.], ...}