where is the toolbar in the new UI? i'm especially looking for the back/forward arrows

Hello Shalom Ben-Zvi. Regrettably, the Main toolbar was disabled in the new UI. Instead, you can add actions you need to other parts of the interface; please, follow this instruction in our documentation to do it. 

Thank you.

unfortunately i can't find the back arow action

The Back and Forward actions can be found in the  Main Menu | Navigate  section:

Olga Mulina  I got it!

Thank you very much!