First, go to the Database and under Items / Item Abilitys. There you can add a new ability to call a specific common event when using the item. Also, hit the switch "available on maps" to on.

For the layout not to be closed, it´s a little more complicated:
In the layout tool, copy the Item Selection and Item Target Selection Layout. (You can only change things, when you make a copy or create a new layout)
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So... In both layouts there are 10 Items listed. When you click on the container button look to the right under control. There you can set an action (which is executed when you click on the item) Set the action to "Call Common Event" for all of the 10 containers.
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Now, there is a problem: you can only choose one common event to be executed. But I´m sure, you want different actions for different items, right? So you need to make a common event, which checks, what item was selected. In the layout properties, you can set a variable to assign a selection result. You´ll need to check this variable via conditional branching and finally, call the common event you want to be executed. It took a long time for me, to figure this out. I really wish, the devs would make more tutorials on the software...