1. Log in to your Network Solutions account.
2. Navigate to Email & Productivity, then select Google Workspace.
3. Choose the Google Workspace plan that fits your needs and click Continue.
4. Select "I want to use a domain I already own" and click USE THIS DOMAIN NAME.
5. Click the RETRIEVE TOKEN button to be redirected to Google.
6. Agree to Google's terms, generate the transfer token, and copy it.
7. Return to Network Solutions, enter the transfer token, and click SUBMIT.
8. Complete your purchase through Secure Checkout.
9. Monitor the transfer status in your Google Workspace product within Account Manager.
REFERENCE: https://www.networksolutions.com/help/article/add-existing-domain-to-a-new-google-workspace-account