Avalara ECM Manage Exempt Customers

Client is using AVALARA for sales tax and ECM. Avalara is telling the client that they need to upload all customers - it is my understanding that there is funcitonality to Manage Exempt Customers and add to Avalara.  We have the tax connector working for sales tax, however when we try to create a customer in ECM provider in Acuamtica, we get an error:  Company is not found.  The company with the ID ‘0’ was not found.  Anyone have insight into using ECM? Is the Tax Provider also used for ECM? There is no option to add a separate ECM Provider in Acumatica.They are logging in through a single account and have only one company.  Thanks!