Add a record to a table using Ninja Forms

Basic plugin should use Ninja Form to add a record to a custom table after getting default values from another 2 custom tables. Details: We have a 5 fields form which is created with Ninja Forms. At submission the form needs to add a record to a custom table. Prior submission the form fields need to get default data from 2 different custom tables. The default data for the form fields is extracted from the tables based on the user WordPress user ID of the connected user.