Missing Signed Instance Exception

I want to connect 3rd party api to log in the website by scanning QR code. But when I fetch, the response is like this

[business][RECOVERABLE][wix-code-dev-dispatcher] c.w.w.d.d.w.p.e.ContentManagementMissingSignedInstanceException - Missing signed instance in /api/other/login/wx/is_login

How do I create signed instance when I fetch? which api should i use?

Try using Axios (NPM). Probably something wrong in the fetch API…