The binlog mode of logproxy should be used with flink-mysql-cdc, which is equivalent to treating observer + logproxy + obproxy as a mysql instance. In this way, the connection information uses jdbc (that is, connecting to obproxy).
Reference to https://nightlies.apache.org/flink/flink-cdc-docs-release-3.1/docs/connectors/flink-sources/mysql-cdc/

It is recommended to use the latest version 3.1.1.