Mobile Data has to be applied to the Ubigi eSIM profile so that you can access the Internet.
To do that, go to:
Settings > Connections > SIM card manager. Under “Preferred SIM cards”, tap on Mobile data and select the eSIM profile you want to apply data to. The tick 
will appear in front of it when it is selected.
Important: When you have multiple SIM cards/eSIMs (“plans”) on your device, it is not possible to activate cellular data on two data plans at the same time. You can only apply it to one at a time.