How can i unlock games?

All of a sudden I want to play a game and it is not possible to buy it in the store although it is free at fortnite etc. They are all blocked and can anyone help me with each account?

It was probably played on another acc.

How do you mean

I only know that from games that have been shared. Go to "Check Licenses" in the Settings.

I don't have it I can't find a license check

Choose Settings then Account Management then click Restore Licenses then click on it so it worked for me and I could play Gta 5 again.

Many thanks but it did not work

If you install a game on an acc and the ps4 is not primary, you can only play it