PayPal Instant Payment Notification warning

I recently moved my PaidMemberships pro to a subdomain.
i.e. from https://australianyogaacademy.com/ to https://ondemand.australianyogaacademy.com/

I am now getting PayPal Instant Payment Notfication warnings.

According to the article at https://www.paidmembershipspro.com/troubleshooting-paypal-ipn-issues/ this error may be because of the domain change.

The article also says that a script can be installed to forward messages from the old domain to your new domain. There are examples for switches from other plugins but not from one installation of PMPRO to another.

Can you provide a script to resolve this issue?

The page I need help with: [log in to see the link]