I just completed a free trial and I would like to purchase a subscription for essentials. the only option that I am being given is to subscribe for Plus.

You should open a new blank QBO Essential and utilize a migration tool if required. If you want to continue using your existing data, you have to purchase your trial account and downgrade it.

https:// quickbooks.grsm.io/US

https:// quickbooks.grsm.io/us-promo