Genymotion Cloud SaaS and Desktop do not support arm64/arm64-v8 applications, even with ARM translation tools.
However, we have recently released a Genymotion PaaS Android 8.0 image which runs on an ARM64 server at AWS. This image can run armv7 and arm64 (arm-v8) applications "out of the box".
If you wish to test, go to https://aws.amazon.com/marketplace/pp/B08KHVZWMJ.