There are two places you can edit or delete an action item in Retrium.
An action item can be edited or deleted either from the Team Room page or from inside the retrospective itself during the DISCUSS phase.
From the DISCUSS phase
Navigate to the right-hand side of the page. Here you can view the action items that have been added by the facilitator. These action items can be edited directly by clicking into the action item itself.
From the TEAM ROOM page
You will see all incomplete action items from the retrospectives that have been run in the Team Room. Here you can edit these action items directly by clicking into the action item itself.