Using this guide you can unlock your DJI FPV video system aka FCC hack.
Use this guide at your own responsibility.
You have to check with your local law regulations regarding transmission frequencies and transmission power.
In order to have a functional unlock you need to unlock both googles and the air unit. Doing the unlock on only one of these devices doesn't help.
After a update, you have have to repeat these steps.
Look for the correct version of your google and do the required steps listed below
Look for the correct version of your video transmitter and do the required steps listed below