You can hook up devices such as intercoms and buttons into the auxiliary cassette of the AC41 and all associated unlock events will be logged in Command.
The Verkada AC41 has two AUX inputs on the 5th cassette. These two inputs are located in the middle terminal block.
The AC41 expects both AUX inputs to be Normally Open (NO).

Wire the Normally Open (NO) output of the external system to the first input of your AC41, using the IN1 input as follows:

Process
From the Devices page select the desired AC41
Select + Add then select Aux Input
Follow the setup flow to configure the aux input