You can refer to the following topics to configure endpoints for an ApsaraDB RDS instance:
ApsaraDB RDS for MySQL
ApsaraDB RDS for PostgreSQL
Enable a public endpoint for an ApsaraDB RDS for PostgreSQL instance
View and change endpoints and port numbers of an ApsaraDB RDS for PostgreSQL instance
ApsaraDB RDS for SQL Server
ApsaraDB RDS for MariaDB