POSTGRESQL 12: pg_basebackup isn't copying postgresql.conf and pg_hba.conf from master to standby
If data_directory in the master's postgresql.conf is set to some non-default value, then the conf files will not be in the "real" data directory and will not be copied by pg_basebackup.

If the person in charge of the master is not you, you should ask them for a copy by some other means.  Or you can just create your own.