Welcome, @Humeyra_YILDIZ_AKKAM
If you just need more working space to store your query/output read data at a public Galaxy server, the guide below should help you to access more temporary space.
I’m guessing that you are working at UseGalaxy.eu, correct? That guide has a screenshot about where to find the request form on the server homepage.
Hope this helps but let us know if not! The server URL could help – find this at the very top of your browser windlow. I don’t recognize which would have exactly 200 GB as the default storage since most I can think of have either 100 GB or 250 GB. 