How do I check if a number exists in the database?

Hello 

Hope this message finds you well

what if I want the 1st step is to enter an invitation number by the member 

( invitation number will be provided to the members earlier ) 

and I want an option to let the form check the entered number if it is already in a list ( which I should provide earlier ) or not ? and if it is registered before or not ? 

is this possible ?

regards ,,,

Have you checked the Spreadsheet to Form widget?

https://widgets.jotform.com/widget/spreadsheet_to_form

Guide: https://www.jotform.com/help/442-How-to-Use-the-Spreadsheet-to-Form-Widget

You can upload the list in an Excel sheet and attach it with this widget. Next, using the unique number you can search this sheet if the employee exists then you can populate the details if not then you can stop the flow.

Hope this helps!

Thanks.