How to prevent users to enter a comma inside of a field?

a un campo especifico deseo que solo acepte el punto (.) y no la coma (,) , en caso que el usuario coloque coma (,) debe mandar un error o un mensaje de alerta indicando que el campo solo acepta punto (.)

to a specific field I want to only accept the period (.) and not the comma (,), in case the user places a comma (,) it should send an error or an alert message indicating that the field only accepts period (.)

You can use a Number field. A comma cannot be entered inside of the Number field.

Here is a demo form - https://form.jotform.com/91471906129965