Mapping custom property field

Hello.
I am working with a website which uses Contact Form 7 forms, and each submission is alredy being recorded on Hubspot.
However, not al fields are being recorded. Default fields like name, phone, email… are being recorded, but I added a checkbox in which the user can select one or more options, but this field is not being automatically added on any property field on the CRM.
How can I map this field to a new, or existing custom property?
Thank you.