API POST call returns 403


I am calling a POST when a button is clicked, and it returns a 403 status code.
It seems to be caused by an unknown term for me: CORS.
From a different post I got this: “If you’re calling grafana from a browser website and the grafana and website runs on different domains you’ll probably need to setup a proxy with support for CORS negotiation.”

Can someone help me out doing this? I am 100% sure that the headers and needed keys are correct, since it works on platforms like Postman and returns the wanted result.

Thank you,