To understand what a license is, please read this article.
To allocate a license to a user:
Ensure you are logged into the Portal and you are a Company Admin.
Open your company's settings by clicking on "Company settings" in the menu on the left.
Scroll down to the "Company Users" section.
Click on the toggle button in the "License" column next to the user you wish to assign a license to.
The user will be immediately assigned that license and, given they are in a team and have the relevant team permissions, they can start to use Safepoint.
Note: You can see how many licenses you have available at the top of the "Company Users" section in company settings.