/radius add service=ppp,hotspot address=YOUR_VPS_IP secret=YOUR_RADIUS_SECRET authentication-port=1812 accounting-port=1813 timeout=3000ms
/ppp aaa set use-radius=yes accounting=yes interim-update=5m
/ip hotspot profile set [find] use-radius=yes radius-accounting=yes interim-update=5m
/system logging add topics=radius action=memory