Pressing keyboard Tab helps to navigate across different focusable elements(input) in the browser window.
Specifying tabIndex = 0 on the non-focusable elements like div makes them focusable. This element would also be included in the navigation order of the page.
The tabIndex = -1 won’t make the node include in the navigation order but this could be focused on click or programticaly like below.
The tabIndex = 1 didn’t work for me at all.