Accessing wordpress backend error

Hello there,
I am sending you this complain regarding backend accessing to the companies website when i try to access it through midtech-me.com/login on google chrome it gives me this error (This page isn’t working midtech-me.com is currently unable to handle this request. HTTP ERROR 500) and when i try doing it in Microsoft edge i get a blank page by using the given username and password how can you help me because i want to access the backend and edit the website to optimize it.
Thank you