Reference:

ArGo on twitter: https://twitter.com/rekpero/status/1420733784979243012?s=19

Documentation:
https://docs.argoapp.live/quick-start/configure-domain/

https://docs.matic.network/docs/develop/network-details/network/#mumbai-testnet

It did auto connect for me after the first error.

First Get Matic
https://faucet.matic.network/

Then get Argo Faucet

Johnny Wu’s great video tutorial
https://www.youtube.com/watch?v=Bbm0Yal86WI