There used to be a website which gave me just nameservers to add on my domain and all the things got done easily. it use to be a specific page for a specific domain type of thing. as like domain listing companies doTry adding a CNAME record with the main domain name (without https://).
Another option is to use nginx as a reverse proxy.
Hmm probably they have a reverse proxy solution of some kind. Could be nginx for example. But CNAME is the easiest option imo.There used to be a website which gave me just nameservers to add on my domain and all the things got done easily. it use to be a specific page for a specific domain type of thing. as like domain listing companies do