Configure database access
The shopspray plugin needs to add certain tables to your solutions' database. Add a connection string to your current connection strings:
<add name="ShopsprayPunchoutConnectionString" [..] providerName="System.Data.SqlClient" />
If you don't want it to use the same database as your solution you can effectively copy your existing connection string and just replace the name to ShopsprayPunchoutConnectionString
Continue your installation process with the development stage.