Sampling in parallel with MatlabStan

I would like to enable parallel processing (parallel sampling of chains) when using MatlabStan. However, the stan()-Matlab-function has no such parameter. Does anyone now how to enable this?

I my “local” file in the cmdstan-directory, STAN_THREADS is set to “true”.

Operating System: Linux Ubuntu
Interface Version: MatlabStan-
cmdstan Version: 2.30.1

Thank you!