Sev-u multiple domain server

kindly i need help regarding publish serv- u server for multiple domain

now i have one server with name ftp.x.com and people using it through https from inside and outside the orgnization,

now it is required from me to add 2 different domains ftp.y.com and ftp.z.com

i read that i couldn't share the listeners through multiple domain and also the certificate.

so any recommendation to achieve this task  without changing the default port  for https between the 3 domains