Hey /e/OS enthusiasts! Source
Google’s been cracking down on unsigned custom ROMs passing Play Integrity checks. To stay on the safe side, you’ll now need to sign your ROM packages with release keys instead of test keys.
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@the306bobby built a script specifically for this purpose. Head over to his GitHub page to grab it and get started.
“You can adapt it for other ROMs as well.”
Prep device tree (for other ROMs)
In your device tree (or common device tree) add:
-include vendor/lineage-priv/keys/keys.mk
Build as usual!