Here are the steps for you to follow to turn your cards into action items:
Step 1. Go to the card you want to turn into an action item and click on the 3 dots icon (ellipsis)
Final Step. Choose the option “Set as Action item”
Note: In case you want to remove the action item on your card you can repeat the same process.
Go to the card you want to remove the action item and click on the 3 dots icon (ellipsis). After that choose the option “Remove Action item”