To add the PO date in the invoice, Please follow the below mentioned steps.
Step 1 - Go to the Sales section >> Click on Invoices >> Click on Create Invoice
Step 2 - Kindly click on Custom headers
Step 3 - Click on (+)New custom field
Step 4 - Give the label as PO Date and choose the type as Date and Save
Step 5 - Please note that the toggle button for both i.e. (show in Image and Active) should be enabled.
Turn on required toggle to make it as required custom field while creating Invoice.
Step 6 - There you will get an option to add the PO Date.
