Scheduler - Configure the number of reader/writer threads by cli


I’m trying to create a new couchbase bucket by the commandline tool couchbase-cli. However, I can’t find any parameter to specify the number of reader/writer threads.

So, basically, I need to do from command line this same setup:
curl -v POST -u user:password -d num_reader_threads=8 -d num_writer_threads=8

Thank you very much in advance!