This flow was working when there was only one condition (PO Number). If there the newly created item's PO number exist in the list, it will send an approval email. If there wasnt, it will be approved automatically. When I tried adding the other condition (both PO Number and Client Name), it doesnt work anymore. It will just approved automatically.

My expression in Condition 2:
length(outputs('Get_items')?['body/value'])

I am not really sure where I did wrong. I made sure the column names are correct based on the URL link.