Do not enter your ShipStation username and password in the Plugin tab!
In the Username field enter your ShipStation API Key and enter your ShipStation Secret Key in the Password field.

Need help finding your API and Secret Key? Find out how to generate them here: https://help.shipstation.com/hc/en-us/articles/360025856212-ShipStation-API

One you've generated your API Key and Secret, you can start using the workflow action "ShipStation Send Order" when an order is placed.

New product will appear in the "Manuel Orders" section of
ShipStation.

You can also edit an existing order that you've already sent to ShipStation by sending another request with the same exact  "orderkey".

Link to editor: https://bubble.io/page?type=page&name=shipstation&id=agile-qr-code&tab=tabs-1