Conditional Formatting for a Modified By Column

Andy_B

I am trying to create an automation or formula to populate a cell. Here's the gist of what I am trying to accomplish:

Only when a completed box in a column is checked → I want to populate another cell in that row with the Current User who checked the box. I would like this to populate automatically through the use of a formula or automation.

What is the best way to accomplish this?

Spoonhead

Addd three columns: "Completed" (Checkbox), "User Who Checked" (Text/Number), and a "Helper Column" (Dropdown with user names or emails).

Create an automation workflow that triggers when "Completed" is checked and updates the "Helper Column" with {{Modified by}}. Then, in the "User Who Checked" column, use the formula =[Helper Column]@row to display the value from the "Helper Column". This should then automatically populate the user who checked the box.