Mapping Contact Form field to Custom SFDC Field

Hello,

I use contact form to gate asset downloads on my website. I’ve created a custom SFDC text field for the Lead object called “Asset Download,” and I’m trying to map a hidden field from the contact form that includes the name of the asset to this new field in SFDC. However, I do not see this custom object appear in the drop down window of available fields. I’ve tried refreshing the objects and the fields in the plugin, but still the “Asset Download” field doesn’t appear. Is there any reason why?

Thanks!