Leads using Yes/No UDF

Greetings Team,

We are (or we wish to) start utilizing "Leads" within Maximizer. Using the API to obtain which of our UDFs are attached to Leads, we notice that no "Yes/No" UDF fields are displayed, and we cannot assign "Yes/No" UDFs to Leads (only Individual, Company, or Contact)? The link below states that is can be done:

https://support.maximizer.com/hc/en-us/articles/23137751096717-Create-a-User-Defined-Field-For-the-Leads-Module

Please advise, because some of our "Yes/No" UDFs are needed for our Leads.

Thanks, Joe