UsageX11 forwarding needs to be enabled on your ssh session in order to be able to use xmgrace. To do this, ensure that the -Y flag is used when starting the ssh session
$ ssh -Y firstname.lastname@example.org
The grace module needs to be loaded into your environment by running:
$ module load grace
will launch the X11/Motif frontend. Example data files are located in the doc folder of the Grace installation. Graphing a data file is done by passing the path to the file as an argument to xmgrace:
$ xmgrace doc/10.1.dat
gracebat can also be used to perform rendering in batch mode. See complete documentation in the official Grace User Guide.