Como adicionar uma numeração automático em um campo numerico

tenho um campo chamado numero de chamado e gostaria que esta numeração tenha o seu valor crescente automaticamente, como posso fazer isto 

Atenciosamente.

Marcos Cesar

I have inspected your form https://www.jotform.com/61965094534665 and your field "Número do Chamado" is Submissions Counter widget. This widget is used to count number of submission of your form. Currently your form has 0 submission and because of that number 0 is shown on your form. Each time your form is submitted that number will automatically increase by one. 

I have cloned your form and made two submissions on my form. Number that is shown for my field "Número do Chamado" is now 2. 

Here is my form: https://form.jotform.com/61966685969987 

Feel free to test it. 

If you want to achieve something else, please explain in more details what you are trying to achieve. 

Let us know if you need further assistance.