Pulling in Structure entries as radio button options in Sprout Forms
Sprout Forms v2.3.0 adds front-end field support for Entries, Categories, and Tags Relations fields.

By default, the fields will display a multi-select field on the front-end. If the limit is set to 1, they will display a dropdown field.

The fields are designed to work for simple use cases. If you have hundreds or thousands of entries, you may need to consider a custom front-end field type for your scenario.