When I use this KB https://support.f5.com/csp/article/K24493695, I have the following icon in webtop:
How can the RDP be published using the bellow RDP client in webtop itself.
So when you press that icon from the webtop it should download a rdp file.
That file is only valid for about 5 mins and will load up your session via the f5.
Just a note of warning, the SSO config needs a tweak so make sure its turned off in the first instance.
The default domain parameter in the SSO config for RDP doesn't exist.