Hi @Anonymous,
First of all you want to setup a column filter. Make sure you configure it to use the approval column in your trigger action.
Step two is checking what the value is of the updated approval column. We need to make sure it is Yes. For that we can use a trigger condition.
Just to double check. Your field is a choice field and not of type Yes/No, correct?
If so, you could use an expression where you check the choice value Below is an example.
Replace approval by your internal field name and 1 by the choice option value of your choice list.
@equals(triggerOutputs()?['body/approval'], 1)
Otherwise if it is a yes/no type of field you can simply use this:
@triggerOutputs()?['body/approval']
