how to derive approval comments entered by user in the reason popup into a CPQ quote attribute?

Summary:

This is a new requirement for our project where we want to  derive approval comments entered by user in the reason popup into a CPQ quote attribute.

Content (required):

Requirement -> this is a requirement from the customer side to add booking comments information on submit button when the reasons popup appears.

The steps are :

1. Add a new field/ attribute on Commerce for repair line of business under the booking/factory order tab.

2. Place it under the Booking Comments box and call it "Booking Approval Comments", write back the comments from the "Submit Comment" popup when submitForBookingApproval clicked, and then Submit.