"I have" section in the Currency Exchange

Hi,
In the thread "Content Update 0.3.0 — Path of Exile 2: The Third Edict", it is stated:
You can now Ctrl + Left-click (or the controller equivalent) on an item in your inventory to fill the "I have" section in the Currency Exchange.

I can't find the "equivalent". The issue is happening while using controller input (to clarify)
Asked the question on Reddit and the POE Discord, but no solution was found.

Has anyone else come across this issue?
or
Is there actually a command for controller to set "I have"