Took a look at your code, thank you for linking it in the other thread:
The HologramCloud command is specific to our Dash API and will only work with the dash. It’s likely you’ll have to use commands that are closer to the Digi Xbee 3G module. Our connectivity should work with their modem, but you’ll need to communicate with it using command it will understand.
In this case, you’ll want to view your Digi module documentation, likely talking to it over serial. Then you’ll be able to connect via the SIM to the cellular towers and then you can set our cloud as the endpoint (or you can choose to push the data elsewhere).
This is a common issue, especially since you’re a regular Dash user (thank you!). Because that’s a more integrated solution, we have attempted to make the connection easier for users. Unfortunately these firmware modules do not exist for others’ hardware.