Try these steps:
Connect your PSP to the PC with a USB cable. Take the DLC folder for example: “ULUS10461” and copy it to your memory stick on the PSP/GAME/ folder. Double check that the DLC files are where they should be:
X:\PSP\GAME*DLC Folder goes here\
*Leave USB mode and press select to bring up the VSH menu and select “Recovery Menu”
*Then Select “Advanced”
*Change “NoDRM” to Enabled by pressing the left or right on the D-PAD
*Be careful not to press X else you will change it back to disabled, so press circle two times instead to leave that menu.
*Now press select again and choose “Reset VSH” to apply the changes:
You could apply this PSP and PPSSPP Games.
Hoping it helps you.