Hey Charlie, I struggled with the same issue when I started with automations, it’s a bit confusing, but I figured it out and it’s not hard at all.
First you have a trigger, right? in this case your trigger should be “when record matches conditions” and set as condition “when {Edit Due Date} - is - Today”
Then you have an action. You select “update record” and the same table of the trigger.
For Record ID you select “Record from step 1” > Continue > Record ID
With this you are telling airtable to make the update of this step to the same record that matched the conditions in the trigger.
Then, in the NEXT field of the automation action form you select the field (in that record) that you want to update, NOW you select {Review Status}
After selecting the field you can set the VALUE that you want to update the field to, in this case it is not a value from a previous step, so you can just type ‘Needs Review’ in the box, and you’re set.
Hope it helps