Need Assistance to Create a User Agreement Pop Up in the First Login

Summary:

I'm looking for a way to create a popup window at the first login with a user agreement, that will only be triggered after the first connection/login of the user.

Content (required):

I'm looking for a way to create a popup window at the first login with a user agreement, that will only be triggered after the first connection/login of the user.

Once they click agree it will not popup again unless we modify the agreement.

I would like to know if it is possible to do, or perhaps if there are any documentations or references for this case?