This error will say something like "Access to ABC from origin XYZ has been blocked by CORS policy." This happens when you haven't whitelisted your domain with Hydrogen before deploying the components!
You can easily whitelist the domains you are using from the "API Keys & Whitelists" page, accessed on the top right dropdown menu of the Hydrogen admin portal. Please make sure you separate each domain you wish to whitelist with a comma. When you re-deploy the components, this CORS error will be fixed.