Is there any way to remote in to a Pepwave Max if you do not have a static IP issued by the carrier?
That depends on your definition of remote. If you use the link in incontrol to manage the device via GUI, then yes you can do that.
Since most carriers use CGNAT these days, I won’t discuss when you used to get a dynamic but direct WAN IP address. (dynamic DNS).
If you mean access to all of the LAN side networks and devices, then the answer is no.
This is why we run FusionHubs and have all of our remote Pepwave devices connect via a SpeedFusion tunnel to the HUB. That allows us to manage all remote devices without issue. (CGNAT, WIFI as WAN, Routable WAN IP) You then either use your management Pep devices to connect to your FH, or you use any of the remote user access methods to access the FH.
You can of course use a central office Peplink router (or any other Ipsec device), but it seems that using a FusionHub is the simplest, and is easy to maintain.
Built-in to inControl you can access the web admin UI of devices. That would be easiest.
Other methods would require some site where you have a static IP and backhauling traffic over VPN. That could also be a cheap public cloud provider where a static IP is cheap add-on. I pay $8/mo to host a hub with a static IP at vultr san jose data center.