If the server has internet access, you could use a third-party service like https://keygen.sh https://keygen.sh to handle licensing. You could validate their li

If the server has internet access, you could use a third-party service like https://keygen.sh https://keygen.sh to handle licensing. You could validate their license periodically e.g. on application boot, etc. and even lock it down to only be valid on a single machine/server via domain/IP (or some other form of fingerprinting). I'm the founder of Keygen, so happy to answer any questions and help out in any way!