Login from another page


I designed my webpage with wordpress. Now I like to have one page by menu
to have a form with username and password for nextcloud.
So if I give the username and password I come to the file page from nextcloud.
Have someone a idea how I can manage this ?

My main page is example.com my nextcloud page by nextcloud.example.com.

Why in this version ? I like to have the same design for all of my webpages and services in my LAN.

Question … how can I bring some code to this thread ?