Yes the addition of a foot switch can allow the V-Series or IRIS panel operator to activate talks via logic input 1 and logic input 2.  On a 1 RU panel the top row left hand most keys on the panel will activate via the logic inputs.  If the user wants the talk activation to be momentary then the talk keys will need to be either global latch or local latch disable, this can be accomplished either via the cards and ports menu for the specific port name or via the local advanced menu / latch disable function for a specific panel. 
Please remember that the talk activation for logic input 1 and logic input 2 trigger specific key locations on the panel, so the talk key labels have to be programmed on these specific keys. 

Alternatively , you can program the logic 1 or 2 inputs on the panel to make any route in the system select Logic input > route > then select the route (panel, 4wire, interface, conference, group) that you want to make:

ECS

For EHX

Logic input can be configured on Cards and Ports section, Logic Input options: