Rocketchat do not need a domain ending

Rocketchat is an ioen source app to install on any server you like. With the sub domain .rocketchat implementet station accually can only reach the main/dev/test server bat nor privat instances hosted with any domain type you like

chat.mydomain,com
mydomain.com
mydomain.com/chat

all possible in apache and ngix configuration files so your app shouldnÄt add .rocketchat to the app.