When I try to sideload the apk, I get this error on my Quest 2 headset

Fading Light Antiworld_20221027_1824_itch io_1.00_sign.apk: /data/local/tmp/_stream.apk could not be installed [INSTALL_PARSE_FAILED_NO_CERTIFICATES: Package /data/app/vmdl394812437.tmp/base.apk has no certificates at entry AndroidManifest.xml]

What is the difference between this paid for version on itch.io and the free one on the Oculus store?