I already have a modem. Do I need to wait for spectrum to send theirs or can I just use the one I got

I have a Netgear night hawk DOCSIS 3.1 modem. I’ve used it with spectrum at my old apartment.

I’m moving today and when I switched apartments they said I’d need to use the spectrum modem they’re sending out. Tech support wasn’t helpful on determining if my current modem would work

I don’t see why not, my current modem is set for the speeds I’m getting and I don’t want to be out of internet till I get their modem.