Can’t map form fields to zoho fields

I connected one of my gravity forms to Zoho. However, when I click on #4 Map Form Fields to Zoho Fields, then select the Created By / Standard Field / it does not show any fields to map it to under Select Field.

It shows the 6. Choose Primary Key lookup–but nothing shows up in section 4.

The system confirms that it is connected to Zoho, but the options don’t show up on the “Select Field” pull down.

The page I need help with: [log in to see the link]