How do I progress? Inverters Batteries G99

[sharpener]

I am not 100% sure. Mines grid tied and the system wont work when the grid is down.
It is possible (if wired so) to connect the invertor to a generator for when power is down - common set up in south africa where Sunsynks are popular and the grid is iffy, so i would imagine that would connect into the same GEN connection on the inverot, so more than likely its one or the other option to choose.

IIRC the GivEnergy hybrids are certainly like that, only one set of Aux terminals so you have to choose which single function you want.