When you create a text field, you can set its adjustment to "justify (all characters)" (you have to expand the paragraph panel for that, it's the most right adjustment). Then the text you enter is automatically distributed.
Otherwise, you can also emulate that behaviour in one of these two ways:
- You can either change the distance between the character manually by increasing the tracking in the character panel (I don't know its correct english name); it's the control with the "A V" and the arrow below.
- Or you can split the text field into one for each character and distribute that equally using the align panel.