Running jobs on PBS pro with more threads

Hi

I’m having trouble with running bwa-mem on multiple threads.
Here is my job_conf.xml

<job_conf>
        <plugins>
                <plugin id="pbs_drmaa" type="runner" load="galaxy.jobs.runners.drmaa:DRMAAJobRunner"/>
                <param id="drmaa_library_path">/opt/drmaa/lib/libdrmaa.so.1</param>
        </plugins>
        <destinations>
                <destination id="cluster" runner="pbs_drmaa">
                	<param id="Resource_List">nodes=1:ppn=4</param>
 	 	       </destination>
        </destinations>
</job_conf>

This runs a job on a node but still with 1 thread, should be 4.
I’m running it on pbs server.
What do I need to change exactly?

https://docs.galaxyproject.org/