If you have a Canada or US mobile number, to approve/reject a payment order, you will require an Authentication Code, which will be sent to your mobile number as a text message every time you want to approve/reject an order. To receive an Authentication Code, you will be required to verify your mobile number on your WayPay profile
To verify and update your mobile number, follow the below steps:
Sign into WayPay
Click setting gear icon
Select Manage Profile
Select User Settings and you will be taken to User Information page
Click Change to add/edit your mobile number and then click Update to save your changes
Once mobile number is updated, click Verify (very important)
Every time you approve/reject an order, an Authentication Code will be sent to your mobile number.

You might be interested in the following questions
How do I know that I have a payment order pending for my approval?
Why do I need an Authentication Code or Approver Code to approve/reject a payment order?
Can I approve a payment order without an Authentication Code or Approver Code?
What is the difference between Authentication Code and Approver Code?
How can I get an Authentication Code to approve or reject a payment order?
How can I get an Approver Code to approve or reject a payment order?
How can I approve orders if I am unable to verify my mobile number?
I received multiple Authentication Codes, which one should I use to approve or reject an order?
I am getting an error that my Authentication Code is not valid or has expired?