NethVoice: HT813 not on the list of new gateway models

I see a number of the other GrandStream models for ATA. But I don’t see HT813 on the list.

Is it possible to set up a selection for HT813 in new gateway models? Or is it possible to use one of the other models for the HT813.

I notice that when setting up physical gateway. I can not use it with more than one extension.

Furthermore, I have been able to use HT813 with more than one extension on FreePBX - is there anyway to allow the ATA’s like HT813 to work with more than one extension in NethVoice?

Thx
SF