To link a registered ToolBx account to Sandbox the Sandbox customer account needs to be synced to ToolBx.
Linking ToolBx and Sandbox Customer
- The ToolBx Registered account will be listed under ToolBx Accounts

- Sync Sandbox Customer to ToolBx that is associated with the registered account. This will add the Sandbox Customer Account to the ToolBx Account List.

- Open the Sandbox synced account by clicking on the account name. It is the one with
as a verification status.
- Copy the account Number under the account Details at the top right

- Go Back to Account Listing, and open the registered account. Under Account Connection, paste Account Number and click Connect Account.

- The two accounts will merge into one momentarily.

That's all.