The toolbar can be found above the workspace.
There you can select the tool to use for the AI-assisted labeling and start using this feature. The button to activate ai-assisted labeling can only be used if you are drawing an entry with a polygon.
In addition, the toolbar also has sliders for controlling:
Next to them is a button to reset the slider.
In the right corner is also a direct link to this documentation and a modal describing the shortcuts and icons used within the label mode and also containing some information about the loaded image.