https://www.postgresql.org/docs/14/app-pgbasebackup.html doesn't mention "--compress=[{client|server}-]method". That first appears in the v15 docs.
And yet pg_basebackup doesn't complain about an invalid option. (Technically, this is a bug; I first noticed it a week after copying a script from a PG 15 server to five PG 14 servers, and running it quite a few times without fail.) $ pg_basebackup \ > --pgdata=$PGDATA \ > --dbname=service=basebackup \ > --verbose --progress \ > --checkpoint=fast \ > --write-recovery-conf \ > --wal-method=stream \ > --create-slot --slot=pgstandby1 \ > --compress=server-zst ; echo $? pg_basebackup: initiating base backup, waiting for checkpoint to complete pg_basebackup: checkpoint completed pg_basebackup: write-ahead log start point: 256/BC000028 on timeline 1 pg_basebackup: starting background WAL receiver pg_basebackup: created replication slot "pgstandby1" 42567083/42567083 kB (100%), 1/1 tablespace pg_basebackup: write-ahead log end point: 256/BC000138 pg_basebackup: waiting for background process to finish streaming ... pg_basebackup: syncing data to disk ... pg_basebackup: renaming backup_manifest.tmp to backup_manifest pg_basebackup: base backup completed 0