Go to Settings > Personalizations > Miscellaneous > Spoofing;
If you are connected to internet then use "Update Play Integrity Fix", pif.json will be downloaded from chiteroman repo and a pop up will be displayed asking to restart the device. If you are not connected and you have the pif.json file locally then just select it from "Select PIF JSON File" and a pop up will be displayed asking to restart the device.
After the device it's rebooted you will see that device integrity its passing, and probably strong integrity too (until google kill the keybox again). Even if strong doesn't pass, you will be able to update and pass device integrity anytime until google emerge with a "weird" change.