The notifications on the PS4 home screen should tell you if your content is downloaded. Check Notifications > Downloads.
 

If you are unsure if the additional content has been correctly installed, from the PS4 home screen, highlight the game that the content belongs to and then press down on the controller.

This will bring you to the game page. On the left, select Playstation Store.



The window on the right will show you your add-ons. Select Your Add-Ons and press X to see a complete list.



Check if the content you are looking for appears here and is marked as installed.

Sometimes, content that was purchased does not download and install automatically. In those cases, the download needs to be triggered manually. To do this go to the PS Store on your console and look for the item you want to install (e.g. DLC). Once you have located the content, click the button Download.
If the button displays a price instead of a download option, the item is not detected as purchased. If the item was purchased or should be included in your season pass, please contact PlayStation Support.
 

- Restoring licenses
- Power cycle:

1- Turn off the PS4.
2- Disconnect the power cable.
3- Wait 1 minute.
4- Reconnect the power cable and restart the console.