I want to limit the user to fill the limit count of the short test entry field.

I would like to have a minium number of 20 characters on my text box. If the reader does not put the at least the 24 characters, he/she will not go further. Is it possible to to achieve and how?

You can find Entry Limits option under the OPTIONS tab of the field's properties window. You can set a minimum number of characters/words for Long Entry Text fields.

In the example above, turning ON the Entry Limits option and setting the minimum value to 20 and setting the limit type to letters would mean users have to type at least 20 characters(letters) on that field.

i just want to use short text field.
NOT long text field
...

Please note that "Entry Limit" option is also available in 'Short Text Entry" field as well. Please check the screenshot below:

Hope this helps.

Do try it out and get back to us if you have any questions.