Gpay stopped working.. need some urgent help

I had an Gpay app working fine till today afternoon. But my phone speaker stopped working and I had to do a reset of my phone.

Since then the Gpay app has lost the login ability. I get a message as below:

"To ensure your security, please add a phone passcode from your device settings to continue using Google Pay""

Pls help how to do this.

Thanks

/Sachin