Salesforce Integration: unable to map a Lead Object on the form.

Hi, I have established lead generating form with salesforce integration. I have a lookup field (looks for Partner account name) in my Lead Object in salesforce, I want to indicate it's value through Joltform. In the integration I don't see this field. Can you help me out?

Thank you for reaching out to us.

To verify, is this a customized field on your Salesforce, if it is may I ask for the field type of the "Lookup" field? I have checked the integration on your form, and I can't seem to find the "Partner account name" field on the list too:

Can you perhaps share with us a screenshot of the Lead Object on your Salesforce to further verify it on our end? Also, in which field on the form you are trying to map it? 

Please follow this guide to upload your screenshot as we are unable to view images attached to emails: How-to-Post-Screenshots-to-Our-Support-Forum

Thank you. Looking forward to your response.