Info on 'sieve_pipe_bin_dir' needed

I'm trying to follow the instruction https://doc.dovecot.org/2.3/configuration_manual/howto/antispam_with_sieve/ to setup IMAPSieve

I cannot find any info on what sieve_pipe_bin_dir should point to. Any references I have found to this point to the old wiki.

My current spam learning sieve scripts are in file:/home/vmail/sieve/global/ Should sieve_pipe_bin_dir point to this?

Thanks, Leo