Hello 
,
I have a project to add all 42 locations for the same business. There is one verified location and wondering can I add all of them at once or should I add manually and request verification mail (3-4week waiting period).
thank you
You are reaching the wrong community, @Valon
If you want to add and verify 42 different location for the same chain, you are the business owner, or you are an agency, working for businesses.
In both cases, the right place to ask is the Google My Business Help Community
Gaining points through your business activity is against the Local Guides Program Terms and Conditions : “Organizations, brands, and businesses are not eligible for the Program.”.
Hope you will keep this in mind for your future contributions