In QBD you will go to your customers and click on customer center which will give you the list of all the customers

Right click on a specific customer from the list and choose edit customer 

Whatever name (customer name or company name) you want to sync to Payportal as the customer name should be insert it the customer name field. This is separate than the full name and company name 

These Steps will be the same when creating a new customer but instead of edit right below it you choose Add New 

After these steps are completed you hit updated selected on your webconnector 

Login to Payportal 

Go to the customers tab from the dashboard

Verify the customer name appears how you inserted it on QB