Access to content protected by CBSubs is entirely based off the subscription duration. So I suppose you could disable free logins without a subscription in CBSubs > Settings > Global then give users a subscription with a short duration. When it expires their account should get disabled. So they could have access for 1 day.

The other option is to use CB Auto Actions and a field to toggle if the account has been logged in or not. After the login trigger set the field to 1. Then another action on the after login trigger checks if the field is equal to 1 then do a logout. That would allow accounts to login only once for example.

If you're just wanting to send a download URL that gives access as long as they've logged in once then no it can't do that. Typically downloads will be provided by a download extension. If you mean direct downloads by linking to the file directly then it's maybe possible by using the folder access integration that uses htaccess login to protect a server directory.