Error message re writeable folder

Howdy.

I am getting this error with the Pro version:

The plugin needs to create the following directory “/wp-content/uploads//adbc_uploads_x8z8fjl0b251” to save the scan results but this was not possible automatically. Please create that directory manually and set correct permissions so it can be writable by the plugin.

I’ve created the folder, but how do I set the correct permissions and indicate that this plugin can access to write to the server?

Cheers,
Phil.