xpenology access with a synology on fixed public ip

[Cirea]

Hello, I have a synology (ds413j) with a domain provided by synology. I have good access from the outside. I installed xpenology on the same network on a second-hand NUC. I want to be able to access this xpenology from the outside (for example on photos, or wordpress, or other...). I created subdomains like ubooquity.xxxxxxxxxxxx.domainesynology on the synology with a reverse proxy and I can't access... locally it works, thank you for your help or a tutorial?.... cdlt , Cirea