# Custom Domains UAPI Gateway assigns a unique second-level domain for each created API group, which you can use to access the APIs under this group. Protocol + Domain + Path + HTTP Method are used to confirm the uniqueness of the API. Please notice the assigned second-level domain is only for development and debugging, please use a custom domain for accessing after the API is developed. For custom domains, make sure your domain satisfies the following conditions: * The custom domain needs to be registered in the ucloud filing system, please log in to the ucloud filing system to check your domain's [filing status](https://console.dezai.com/site/beian/index.html) * Ensure your custom domain has been CNAME to the second-level domain of the API group. There is no verification when binding the domain in the console, if not parsed it may cause access errors. * If you need to change the API group bound to the custom domain, you need to unbind first, re-parse, and then bind to the new API group * If the APIs under your API group use the HTTPS protocol, you also need to upload the SSL certificate and private key. Operation steps: Enter the API group details, click "Bind Domain" in the right column of Custom Domain, enter "Custom Domain", "SSL Certificate", "Key". Click "Confirm"