You will need to sign into ProPresenter in order to use the software without a watermark on your output(s). If you have a license key or unlock code, check out THIS ARTICLE for information on registering your software. 

With ProPresenter open you will navigate to the ProPresenter Menu, hover on "Settings" and choose "Account" OR you can click “Activate ProPresenter” in the top right of the software.

Once in the Account tab of settings, click the button that says “Sign In” which will open a web browser.

Enter your email address and password and click “Sign In”

You will then choose, what subscription you want to activate a seat from and then click “Continue”

It will then ask you if you want to open ProPresenter, so click "Open ProPresenter"

Finally, it will pop up ProPresenter and tell you the seat is active.

Hit “Get Started” and you are logged in.