If you were using ShipBob’s old real-time rates app, you will need to switch over to CartBob. To do so please follow the steps below.
Step One: Installing CartBob
Follow instructions in this article to install CartBob.
Step Two: Removing ShipBob Carrier Service App
From your Shopify store (admin view), on the side navigation menu, at the bottom, click Settings. Then click Shipping and Delivery.

On the top panel, click Manage Rates.

Scroll down to Shipping from panel. Go to Carrier and app rates tab. Click on ... next to ShipBob Carrier Service and choose Delete.

Note!
If you have several shipping zones, please make sure you remove the app from them as well.