who hold account administrator on azure CSP subscription?

Question

my company starting to migrate PAYG subscription to CSP subscription. but still pending, because my supervisor need explanation who hold account administrator on CSP subscription.

even i login to tenant csp portal, still i must contact csp support to make subscription under csp tenant

and theres foreign principal group on IAM rules, which is holding owner rule, of course i can change it to request support contributor role

but i still want to know, who hold high account admin for that csp subscription