YAML configuration of the Xiaomi Aqara integration has been deprecated, please remove the xiaomi_aqara platform from your configuration.yaml file.
Xiaomi Aqara Gateways are discovered automatically and show up under “Configuration”-> “Integrations”, from there click on configure and go through the steps. If your Xiaomi Aqara Gateway does not show up automatically, go to “Configuration”-> “Integrations”-> press the “+” icon -> search for “xiaomi_aqara” and enter the setup. If no key is provided during setup, only the binary_sensor and sensor platforms will be available. A key is required to activate the other platforms.