Put an input element on the page…style it so it looks like plain text and check the input is disabled

Then next to it put the edit icon and workflow for when it is clicked to change a custom state on any element you want and make a conditional on the input element that when met, will change the style to look like an input, will also make it enabled

You can not dynamically choose the field to update because the field choice is not dynamic…you could set conditionals and create even more development work to have a conditional for each workflow update action to determine which field to update.