How to create a postgres user that auth by AUTH_REQ_MD5

How do I create user that required AUTH_REQ_MD5 or config database so that
it require AUTH_REQ_MD5 ?

I need to reproduce the following issue where postgres failed to login and
I can confirm that the raw username/pass is perfectly fine and JDBC is
happy to connect if only it's not AUTH_REQ_MD5. I dont know how on that env
it ends up being the case.

org.postgresql.util.PSQLException: FATAL: password authentication failed
for user "hoaphan
"
at
org.postgresql.core.v3.ConnectionFactoryImpl.doAuthentication(ConnectionFactoryImpl.java:516)
at
org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:141)
at
org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:192)
at
org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:49)
at org.postgresql.jdbc.PgConnection.<init>(PgConnection.java:195)
at org.postgresql.Driver.makeConnection(Driver.java:454)
at org.postgresql.Driver.connect(Driver.java:256)
at
com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:136)
at com.zaxxer.hikari.pool.PoolBase.newConnection(PoolBase.java:369)
at com.zaxxer.hikari.pool.PoolBase.newPoolEntry(PoolBase.java:198)
at
com.zaxxer.hikari.pool.HikariPool.createPoolEntry(HikariPool.java:467)
at com.zaxxer.hikari.pool.HikariPool.checkFailFast(HikariPool.java:541)
at com.zaxxer.hikari.pool.HikariPool.<init>(HikariPool.java:115)
at
com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:112)
at
org.flywaydb.core.internal.jdbc.JdbcUtils.openConnection(JdbcUtils.java:56)
at
org.flywaydb.core.internal.database.DatabaseFactory.createDatabase(DatabaseFact

Regards,

Hoa Phan.