The Custom Field in BigCommerce could be added using the Commerce Connector from the Entities form(BC202000).
Imagine you would like to map a attribute or custom field or any field from Acumatica Stock Item form to a custom filed in BigCommerce product page and this custom field in BigCommerce is not yet created.
- Go to Entities form(BC202000), select Stock Item Entity.
- Go to Export Mapping Tab
- Click plus (+) button
- In the Source Object, select the required Acumatica object. Eg: Attributes or Advanced
- In the Source Field/Value, select the required Field.
- In the Target Object, select the object as Product->Custom Fields.
- In the Target Value/Field, select <<Automapping>> as shown in the screenshot.
Now when the stock item is exported next time, connector will automatically create the Custom Field in BigCommerce with the same name as in Acumatica. If the field already existing in BigCommerce then just the value of the field will be exported to existing field.


Limitations:
- Connector does not allow deletions. If a field is created then user must go and delete manually. So be careful to not to create custom fields unless it is created.
- Custom fields in BigCommerce(BC) is required field. So while creating the field if the value of the field is null in Acumatica then custom field will not be created in BC.
- Custom field will be created for all the items of the entity. It is not pertinent to a single stock item.
- Customer and Customer Locations in BC does not support custom fields. They have something called as form fields.
- For Form field, user must create a form field in BigCommerce first and then map it from Entities form.
