If you are collecting entries directly from a public form (shared using its permalink), you must enter the Thank You page URL (For example: https://forms.zohopublic.com/zylker/form/ProductEnquiry/thankyou ) as the conversion URL in Facebook pixel.
Else, if you are collecting entries from a public form on your website, you must enter the form's public URL (For example: https://forms.zohopublic.com/zylker/form/ProductEnquiry/formperma/lS03Ipzv7zbddPURZbiJwlONJfbgMH2e7NlmM37hHEk) as the conversion URL in FB pixel.