Upgrading Inverter Grounding Question

RTWCTS

I am planning to upgrade my stock 1200W inverter to 3000W. Looking at the install manuals for several products, they all specify chassis grounding the inverter and a specific lug to do so. Looking at my AIMS, factory installed, inverter there is no wire attached to the chassis ground lug. Where should the ground from the inverter attach to the trailer?

Edit to add: My first thought is to run a wire to the ground terminal block that is behind the power panel (WFCO).

Thanks in advance…