How to access App Store Connect without enrollment?

Hello guys,
I'd like to operate Apple search ads Advanced so, I create my account for Apple search ad,
And to make my first ad campaign, They request me to link my account with App store connect account,
so I try to create one. but they reuqest me to enroll Develoment program or be invited to admin acoount. (I don't have anyone who get admin role)
I'd like to know I really need to purchase membership also, and Is this only way to create ads campaign in Apple search Ads advanced.
(It's tricky.. I don't understand why I enroll development program. I only wanted to operate App campaign! )
Please help me.
Thanks