No worries. I understand. To use the AT you need to reconfigure your inverters from parallel operation to split-phase. In other words, L1 would go to one inverter and L2 would go to the other. The wiring diagram you seek is in the AT manual. I’ve snipped it out of page 3 for you here:
L1 exiting the AT would go to one side of your RV load center and L2 would go to the second side of your load center. The AT would then balance loads across the two inverters up to a 28A difference.
Also, take a look here: Solar power trailer | Off-Grid Power Systems
This is our solar trailer that we also use for demos and on-site trainings. It has a 50A shore power input. The inverters are configured in split phase and the AT balances 120V loads evenly across the inverters. This is the configuration you should choose with your existing inverters assuming they are the regular 120V inverters and not the 2x-120V inverters.
If you are using two 2x-120 inverters in parallel then an AT isn’t going to do anything for you anyway. If the inverters are in parallel mode, they will balance themselves.
This might be a case where you would want to consult with a local trained Victron installer, especially if you aren’t clear on the difference between a parallel inverter setup vs split-phase.