You'll need to log in as the admin of your Amazon Seller Central account. Only the admin can approve the connection.
Steps
Go to Manage Stores & Files and click "+ Add Store" at the top right (or the "Add Stores" tile if you have no stores yet).
Click Connect on the Amazon box.
Pick your store's region, for example the United States or the United Kingdom.
United States only: If you also sell in Canada or Mexico, turn on "Add Amazon.ca" or "Add Amazon.com.mx". They'll be added in the same step. If you use Amazon Warehousing & Distribution (AWD), turn on "I use AWD Inventory".
Type a Store Name for each store. This is the name you'll see in ConnectBooks.
Click Connect.
Amazon Seller Central opens. Log in and approve ConnectBooks.
Back in ConnectBooks, you're asked to link your PPC (ads) account. Click the button and approve it, so we can show your ad costs per product. Don't run ads? Click "Skip & Continue", then "I understand, Skip".
That's it. ConnectBooks starts bringing in your sales, fees and inventory.
Frequently asked questions
I sell in other regions, like the UK or Europe.
Add each region as its own store. Only Canada and Mexico can be added together with the US.
What if I skip the ads step?
Everything else still comes in, but we can't show your ad costs per product.
It says the store name already exists.
Each store needs its own name. Pick a different one.
Can I turn AWD on or off later?
Yes, in the store's settings.