Module development for Drupal 8?

Question

Drupal

Hello. It is necessary to make a module for drupal 8, which allowed the admin to publish files with a password for downloading them, and could also add a description to it. From the user's side, the page will display the file itself, its description, and the download button, which, when clicked, opens a window with a password. There is an eye icon in the field, when clicked, the password becomes visible. If the password is entered correctly, the file is downloaded, if not, the corresponding message about the wrong password. Tried to make a form module but ran into a problem. I don’t know how to display the file name and description with a button on the page and store files not in public storage, but in private