You need to provide your Parcel Pro API Credentials and save them in the app settings page.
Go to Admin > Apps > Jewelry Solutions > RapNet integration section and provide your API credentials.
If you do not have a RapNet Pro account yet, apply for one here.
API credentials are not your regular login and password. It is a different identification and RapNet should provide to you. If you have an account with RapNet, but do not have your API credentials yet, you should request them here.
Learn more about RapNet here.