Using #DATA_QUOTA# on the captive portal login page for BR1 Routers

I’ve been able to successfully use the #DATA_QUOTA# in the text of the ‘success’ and ‘quota reached’ pages when configuring the captive portal on the BR1 routers, but it doesn’t work on the ‘login’ page. instead it just shows you the actual text “#DATA_QUOTA#” not the quota value. Is this not supported or is there a trick to make it work here too?

Here’s what the login page looks like when trying to use the DATA_QUOTA variable