...
Once this is installed in the "Parallel" > "Create and Manage Clusters..." dialog window, import the configurations:
Correct the location of the plugin installation to reflect your setup : PluginScriptsLocation ($INSTALL_DIR/MATLAB/SupportPackages/R2019b/parallel/slurm/nonshared)
Test your installation with the "Validate" button (the "parpool" test might fail if you don't have a static IP). This may take a long time depending on the current workload of the cluster.