How to add a prompt for gcash reference number in POS

Hi, can anyone help me, i added Gcash as mode of payment in Point of Sale (POS) i want to add a prompt to ask for gcash reference number after the amount in gcash has been entered, how to do this? Thank you.

If you want to add a custom field like “GCash Reference Number,” you can add it to the POS Invoice doctype. After that, you need to include the custom field in the POS Settings so it will appear on the POS screen. However, you will also need to add the logic for this, which means you’ll have to write code or customize the functionality in your custom app.