I enter the same input on a webpage (login). Is it possible to set up a link to that page so that text box will be already filled out?

Yes.
All browser can be set to remember your login details automatically.

Curlyben (https://www.askmehelpdesk.com/members/curlyben.html),

Thank you for your response.

I need probably some kind of javascript to include in a link to the page. So, when press a link on any computer text will be in text box automatically.

Thank you