Business unit dropdown support question

Hello. I’m looking to use the Integration for Contact Form 7 HubSpot plugin to create new contacts on Contact Form 7 submission. Our account have two business units, which show up as a contact property Business units, with a dropdown.

I’m looking for a way to tag the new contact with the right business unit value. Currently, I get the following error:
{“isValid”:false,”message”:”Attempted to insert non-long value Interguard into property hs_all_assigned_business_unit_ids”,”error”:”INVALID_LONG”,”name”:”hs_all_assigned_business_unit_ids”}

I’m guessing this is related to the property type. I’m trying to insert a text value into a dropdown. I did not see an option for the dropdown field type, just a standard field. Does the app support dropdowns to solve this error? Is there another way to attach the correct business unit option?

Thank you in advance for your help. I’ll be more than happy to get a premium version if you can confirm that functionality is available there.