I have what may be an odd situation.
I'm trying to monitor a collection of wifi ip cameras in a location so remote that the only internet access is through a verizon hotspot.
I can log into the cameras if I know their ip address and see the images... until the ip address changes.
There is no computer there, so the router has to handle the changing ip situation.
The router is built into the hotspot (a novatel t1114 combination lte modem/wifi router).
The setup screens for the t1114 make no mention of dynamic dns support but they do allow me to specify the dns servers rather than just let verizon use theirs.
Is that enough to get me the same functionality as a ddns capable router would?

Just adding DYNU as your DNS will not provide what you need. Something at he remote side needs to support a Dynamic DNS client to update dynu if the public IP address changes.
Looking at the manual there is a DDNS tab, however it is not clear it it had built in support for Dynu. If there is nothing else at the site that support a DDNS client and you want to use DYNU, maybe you could install a Raspberry Pi and configure the client on there. It would be cheap, not ideal I know.