When you turn on Google My Business Profile messaging so customers can message. Can you have 2 phone numbers to receive the messages?
The Google My Business Profile messages are not received by SMS, they will appear only on your Google Business Profile messenger..
But you can have 2 phones using the Google Maps access the messaging tab for the same Google My Business Profile. To turn on the Google My Business Profiles Messages follow these steps and to respond to messages follow these.
You will be able to learn more about Messaging in my Google Business Profile Training.