Using multiple threads in the GC "garbage collection"

I use Seafile Community Edition - 9.0.7
In the official “manual” writed about “Using multiple threads in the GC” and do not write that this is only for the professional version. -t 20

Please answer, is it so that this is a feature only for the pro version? if not, then how to run it, the script itself does not know about the option -t ?

AFAIK this is a pro only feature. In pro you don’t even have to stop the server to run GC. So it works totally different than GC on CE.