How To Transfer Saved Game Files System Storage to USB (PS4 / PS4 PRO)
Step 1: Turn on PS4.
Step 2: Insert External Drive.
Step 3: In the Main Menu, Go to "Settings".
Step 4: Click on "Application Saved Data Management".
Step 5: Select "Saved Data in System Storage".
Step 6: Select "Copy to USB Storage Device".
Step 7: Select Game to Copy.
Step 8: Wait Until Transfer Is Complete.