Force First Promoter integration to only work with 1 yr sub?

I want to spin up a referral program for my members. I’m taking a look at first promoter - the goal being to offer a cash incentive for a year sign up.

However, when I make a test user and click through their first promoter link, I am taken to the ghost portal for my site and I can sign up for one month, a free sub, etc. I don’t want to pay people to get me free subs (or one month subs?) – is there a way to force the integration to only offer 1 year subs?