CORS error while using React Front End,

I am facing CORS error while calling my the frappe rest apis from my react app but postman works fine.

Show logs. If you send the cookies and use decorator @frappe.whitelist(allow_guest=True) You shouldn’t have any problems

But if we giving like allow_guest = True means any one can access right? Only Authorized Person need to call this api function from any ware. For this any solution is there ?