Here is my diagram

One physical server located at office as monitoring, and another is at client site
This two have connection/can ping. I already open specific port on client site (1024-65535)
Already tested telnet at port 2805 (it's working)
When I tried to add Client server at Veeam one located at our office, it stated
"Veeam ONE Monitor could not connect to '10.254.1.38'. Access is denied. Please verify user credential and try again"
What else do you think this problem came from?
Support case #03477964