Like all plugins this one uses your existing connection you your WordPress database. This connection is configured through your wp-config.php file on your server and I would not advise changing anything in that file.
If you have created a non-standard table in your WordPress database then you would just need to extend the same permissions to that new table as the rest of the table have for this plugin to query that data as it would any other table.
I don’t know what tools you might have used to create the new table with the wrong permissions but your hosting provider surely have their own tools in your control panel for you to examine and correct the table access permissions.
