Hello and welcome to the forum.
I would think that after you have Authorized Total Studio 2 MAX then all the products would appear in your User Area / My Products:
https://www.ikmultimedia.com/userarea/my-products/You might find it there. If not, then please contact
Sales/Account Support, via here. You will be able to search the FAQs first, but if they do not resolve your issue, there is a link at the top of the Search FAQs page to a Support form. Sales Support can look at your Account and see what's going on. Response time normally is within 2 working days (US (East Coast) Business hours, generally), but in the current circumstances please allow some more time. Administrators and Moderators here cannot access your Account.
As for Registration / Authorization, I am not sure.
-- How many serial numbers did you get?
-- And for what products?
Don''t tell us what the actual Serial Numbers - as someone-else could steal them from you.