TypeError: Failed to execute 'fetch' on 'Window': Invalid value

Question

I\'ve tried to use fetch to call from backend using react, without libs (such as Axios). So I created this function:

export function api(url, method, body, i         


        

Answer 1

For me, i had an invalid character in a key of the header object. I accidentally included the ":" and this throws the error described. Really difficult to visually see in the chrome console. Hope it helps someone.

{ 'Authorization:':'Bearer etc...' }