When I try to login admin its says Connection Refuse and Post request error [closed]

I have a University Dashboard and in that I have some logins such as Admin Login, student login etc. But when I try to put username and passward then its says in inspect POST net::ERR_CONNECTION_REFUSED and message: ‘Network Error’, name: ‘AxiosError’, code: ‘ERR_NETWORK’..
And in the backend side I use MySql and I also provide the database connection but this error happens.

I expecting it will give me login successfully or login.