Automatic Number Generation for Restricted Party ID's

When I manually create a Restricted Party by leaving the <Restricted Party ID> field blank, GTM assigns a <Restricted Party ID>
Do you know where can I find the set-up for Automatic Number Generation for the Restricted Party and set a different value from which it can start incrementing

The issue we are facing is that the number GTM is assigning already exists. Hence we are getting a UNIQUE rule violation.

I want to set this number to something that does not exist currently.