Convert persian or arabic number on Gravity Form fields

I using Gravity Forms on my site but in gravity forms field, Arabic or Persian field is not work. Also I have modified a code to change English number to Arabic or Persian but it does not working.Please help me guys.
Any help is appreciated.

My code so far:

 function _sn_convert_persian_and_arabic_numbers_to_english_numbers__input_number_gravity_form($_sn_html_input_type){
    if(!function_exists("_sn_cpaanten__ingf__add_to_footer")){
      function _sn_cpaanten__ingf__add_to_footer(){
        ?>
        <script type="text/javascript" language="JavaScript">
          var sn_persian_numbers = new Array(/۰/g, /۱/g, /۲/g, /۳/g, /۴/g, /۵/g, /۶/g, /۷/g, /۸/g, /۹/g),//Persian Number
            sn_arabic_numbers  = new Array(/٠/g, /١/g, /٢/g, /٣/g, /٤/g, /٥/g, /٦/g, /٧/g, /٨/g, /٩/g);//Arabic Number
          function sn_convert_persian_and_arabic_numbers_to_english_numbers(sn_string){
            if(typeof sn_string === "string"){
              for(var sn_cpaanten_for_a=0; sn_cpaanten_for_a<10; sn_cpaanten_for_a++){
                sn_string = sn_string.replace(sn_persian_numbers[sn_cpaanten_for_a], sn_cpaanten_for_a).replace(sn_arabic_numbers[sn_cpaanten_for_a], sn_cpaanten_for_a);
              }
            }
            return sn_string;
          };

          var sn_gform_inputs_number = document.querySelectorAll(".ginput_container.ginput_container_number input");
          for(var sn_gform_inputs_number_for_a=0; sn_gform_inputs_number_for_a < sn_gform_inputs_number.length; sn_gform_inputs_number_for_a++){
            function sn_gform_change_value_input_number(){
              this.value = sn_convert_persian_and_arabic_numbers_to_english_numbers( this.value );
            }
            sn_gform_inputs_number[sn_gform_inputs_number_for_a].addEventListener("input",sn_gform_change_value_input_number);
            sn_gform_inputs_number[sn_gform_inputs_number_for_a].addEventListener("keyup",sn_gform_change_value_input_number);
            sn_gform_inputs_number[sn_gform_inputs_number_for_a].addEventListener("keydown",sn_gform_change_value_input_number);
            sn_gform_inputs_number[sn_gform_inputs_number_for_a].addEventListener("keypress",sn_gform_change_value_input_number);
          }
        </script>
        <?php
      }

    return $_sn_html_input_type;
  }
  add_filter("gform_include_thousands_sep_pre_format_number","_sn_convert_persian_and_arabic_numbers_to_english_numbers__input_number_gravity_form");

>Solution :

Generally your code almost complete but there is s little problem on it. So, I have revisited the code nearly completely and managed to fix your issues. The revisited code is:

  /* change English Number to Arabic or Persian */

  function _sn_convert_persian_and_arabic_numbers_to_english_numbers__input_number_gravity_form($_sn_html_input_type){
    if(!function_exists("_sn_cpaanten__ingf__add_to_footer")){
      function _sn_cpaanten__ingf__add_to_footer(){
        ?>
        <script type="text/javascript" language="JavaScript">
          var sn_persian_numbers = new Array(/۰/g, /۱/g, /۲/g, /۳/g, /۴/g, /۵/g, /۶/g, /۷/g, /۸/g, /۹/g),//Persian Number
            sn_arabic_numbers  = new Array(/٠/g, /١/g, /٢/g, /٣/g, /٤/g, /٥/g, /٦/g, /٧/g, /٨/g, /٩/g);//Arabic Number
          function sn_convert_persian_and_arabic_numbers_to_english_numbers(sn_string){
            if(typeof sn_string === "string"){
              for(var sn_cpaanten_for_a=0; sn_cpaanten_for_a<10; sn_cpaanten_for_a++){
                sn_string = sn_string.replace(sn_persian_numbers[sn_cpaanten_for_a], sn_cpaanten_for_a).replace(sn_arabic_numbers[sn_cpaanten_for_a], sn_cpaanten_for_a);
              }
            }
            return sn_string;
          };

          var sn_gform_inputs_number = document.querySelectorAll(".ginput_container.ginput_container_number input");
          for(var sn_gform_inputs_number_for_a=0; sn_gform_inputs_number_for_a < sn_gform_inputs_number.length; sn_gform_inputs_number_for_a++){
            function sn_gform_change_value_input_number(){
              this.value = sn_convert_persian_and_arabic_numbers_to_english_numbers( this.value );
            }
            sn_gform_inputs_number[sn_gform_inputs_number_for_a].addEventListener("input",sn_gform_change_value_input_number);
            sn_gform_inputs_number[sn_gform_inputs_number_for_a].addEventListener("change",sn_gform_change_value_input_number);
            sn_gform_inputs_number[sn_gform_inputs_number_for_a].addEventListener("keyup",sn_gform_change_value_input_number);
            sn_gform_inputs_number[sn_gform_inputs_number_for_a].addEventListener("keydown",sn_gform_change_value_input_number);
            sn_gform_inputs_number[sn_gform_inputs_number_for_a].addEventListener("keypress",sn_gform_change_value_input_number);
          }
        </script>
        <?php
      }
      add_action("wp_footer","_sn_cpaanten__ingf__add_to_footer");
    }

    return $_sn_html_input_type;
  }
  add_filter("gform_include_thousands_sep_pre_format_number","_sn_convert_persian_and_arabic_numbers_to_english_numbers__input_number_gravity_form");

Code goes in function.php file of your active child theme (active theme). tested and works.