This guide will let you know how to co-op with your friend on PS4 (Workaround for Couch Co-op). Just go through the guide and follow all the step-by-step instructions to play co-op.
You will need to have two controllers and a spare PSN account. Press the start menu button and then press the playstation button on your second controller, then select a spare PSN account.
After that, you have to set up a party chat that will include your primary and spare accounts. Invite the person that you want to co-op with. Press the playstation button from your second account and head over to party chat.
Now you will need to tap on the Share Play option. Once the share play is started, you have to click on that and then tap “Go to Party for Share Play”.
After that, click on “Give Controller to Visitor” and then “Allow the Visitor to Play as You”.
Now you will be able to co-op with your friend.