What type of infra setup is it? Don't see virtualhost https://docs.apigee.com/api-platform/fundamentals/virtual-hosts Make sure it is done before you start working on proxies..
Some information on getting started -> https://docs.apigee.com/api-platform/get-started/get-started
Under Admin > Environments > Groups, there should be an Environment Group that contains the environment you have deployed your API Proxy to. Check the hostname that's defined for this environment group