How to connect external models with User id?

Question

Hi to everyone.

 

I am trying to build multiuser website. I am facing an issue related to users profile data. I can register and change some details of my profile but I don't know how to let registered user to add additional information to own profile page such as Address, Description, Other Information and etc. I have created external model and tried to connect it with user id , but failed to do so. Do you have any related experience. It already took my 3 days to clarify but no result. Please help

 

P.S I am new to web development and to Asp.Net core. Thanks in advance for your time and effort to help me

 

Best Regards