Form personalization for GST number format.I

Hi,

I need to make a personalization that when we are entering a GST number if it is not in the exact format as specified below, I need to stop them from moving to the next tab and throw an error.

I am using R 12.1.3 VERSION.

•   The GSTIN consists of 15 digits
•    The first 2 digits can range from 01-35 and indicate the state code for the registration as per the Indian Census of 2011
•    The next 10 digits are the PAN number of the GST registered entity
•   The 13th digit of the GST Number is the entity code. It refers to the order in which registrations was made by a legal entity that has multiple registrations within the same state. In case a single legal entity has 2 business verticals registered within the same state, the first registration will have 1 has the 13