Grace period for Studio One purchases that quality for Studio One 5 is 90 days. (ie beginning of April, 2020)
If you registered Studio One Artist 4 or Professional 4 in the last 90 days check your MyPreSonus account.
Customers can choose between S1 or PreSonus Sphere for a set amount of time.
If you're not sure, log a support request through your https://support.presonus.com
so one of the team members can help you.