Router RB951 + 24 Volt

Hi
one of my customer buy a Router RB951 and he ask me if he can plug it on a 24 volt UPS for his automate.

The sheet in the box say yes it can from 9 to 30 Volt.
Our question is, can he power it over the DC wire on a device that give 24 volt or he need to plug it via PoE 24 volt to make it work.
Thx
and sorry for my not so good writing

He can use 24v directly to the power connector.