With four selling channels, Magento, Shopify , Wix, and Big Commerce, we can send live rates for customers at checkout. See our Send Rates to Store Checkout article to learn more.
For other selling channels, ShipStation cannot send live rates for your customers to select at checkout at this time.
Many selling channels provide access to plug-ins so you can provide live rates from your carrier account to your customers during the checkout process. You will need to contact your selling channel for details.
Stay tuned! We are working with our partners to expand these options soon!