Pay-as-you-go pricing through AWS, Azure, or GCP. This is often cheaper for short-term testing than a yearly license.
Instead of searching for keys on GitHub, you can access Genymotion through official channels: Genymotion Personal Edition genymotion license key github
If you are looking for a key to start using the software, Genymotion offers several legitimate paths: Pay-as-you-go pricing through AWS, Azure, or GCP
During the installation or first sign-in, the wizard will ask for a license. Select the option for "Personal Use." Pay-as-you-go pricing through AWS