Accept - HTTP | MDN
The HTTP Accept request and response header indicates which content types, expressed as MIME types, the sender is able to understand. In requests, the server uses content negotiation to select one of the proposals and informs the client of the choice with the Content-Type response header. In responses, it provides information about which content types the server can understand in messages to the requested resource, so that the content type can be used in subsequent requests to the resource.| MDN Web Docs
