The payment widget allows you to include the GigaBook payment collection form on your website.
From the "Promote" icon in your settings ribbon, select the "Payment Collection" option. 

From there, you will be taken to the Payment Widget Configuration page to begin your customization. In here, you can make changes to your widget template's appearance and messaging.

Edit any of the following to best represent your business:
Colors
Fonts
Preferred Client Information
Size

You will also see an Advances Settings option within the configuration page.

This allows you to customize the messaging your clients see on invoices, billing info forms, etc.
Go to the Payment Widget Configuration Page for more information.