Do I need an Instagram account?

Yes!

The Follower Counter displays the number of Followers you have on your Instagram Professional Account. 

In order to secure their platform, Instagram requires that every communication with a Professional Account has to be initiated by an Instagram user.

PS: That’s the reason why we’re asking you to connect yourself via your Instagram account during the setting up steps.

If you want to create a Professional account for your company, our good pals from Instagram explain the process over there: https://business.instagram.com/