The version of RNA-STAR at https://usegalaxy.eu/ includes
--twopassMode when the setting for Other parameters (seed, alignment, limits and chimeric alignment) is set for STAR-Fusion.
The version at https://usegalaxy.org is in the middle of an update to fix a bug, and the newer tool version will be installed. Once done, the tool could be used there as well. Details: https://github.com/galaxyproject/usegalaxy-playbook/issues/134
Or, you can set up your own Galaxy (local, cloud, docker) and install the most current version from the ToolShed. Update it again once the bug is fixed to capture that correction. https://toolshed.g2.bx.psu.edu/view/iuc/rgrnastar/a70a7eebb435 && https://galaxyproject.github.io/
Thanks! Jen, Galaxy team