Toolshell region to the right side on the screen in Blender 2.9

Normally with blender 2.83 I could toggle over the tool shelf (T) and press F3 and then type
flip to flip it over to the opposite side. In Blender 2.9 this is not possible anymore.
How can I flip tool shelf (T) to the opposite site for blender 2.9

please try it!

  1. Open up the User Preferences / Key map / Screen/ Screen(Global)
  2. Press Add New
  3. Open up the textbox on the left by clicking the little triangle
  4. Rename as screen.region_flip and set the key to F5
  5. Move the mouse over the Toolshelf and press F5