Front and back on localhost. How to share data?

Question

Backend

Front: Vue + Axios
Back: Node + Mongo + Express

Back available at URL: localhost:5000
Front running at localhost:8080

Back waiting for request at URL: localhost:5000/api/post/get-all
Making a request from the front:

request screenshot

But in Preview I see an error:

error screen

What am I doing wrong? How to get rid of the error?

Answer 1

Add headers for cors

res.setHeader("Access-Control-Allow-Origin", "*")
  res.setHeader("Access-Control-Allow-Credentials", "true");
  res.setHeader("Access-Control-Allow-Headers", "*");
  res.setHeader("Access-Control-Expose-Headers", "*");
  res.setHeader("Access-Control-Request-Headers", "*");
  res.setHeader( "Access-Control-Allow-Methods", "PUT, POST, GET, DELETE, PATCH, OPTIONS" );

https://developer.mozilla.org/en/docs/Web/HTTP/CORS

Answer 2

Debugging and logging on the backend
Also, see what kind of headers you are leaving (you can see them in the inspector), maybe you made a mistake and are not sending the expected ones?