below is the plugin command description taken from the help file of the plugin ^^ i hope this helps.
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Plugin Commands :
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command :
set_button_picture PICTURE_ID COMMON_EVENT_ID
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description : make a new button from the picture with the id of "PICTURE_ID"( replace PICTURE_ID with the id of the picture you want to turn into a button ), when the picture is clicked, the common event with the id of "COMMON_EVENT_ID" will be executed( replace "COMMON_EVENT_ID" with the id of the common event that you want to execute when picture is clicked )!
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NOTICE: This command is exclusive to rpg maker mv!!! Please use "Button Picture" plugin for rpg maker mz!