Updated displaySubmit to accept custom data-callback

src/NoCaptcha.php

@@ -82,16 +82,20 @@ class NoCaptcha
      */
     public function displaySubmit($formIdentifier, $text = 'submit', $attributes = [])
     {
+        $javascript = '';
+        if (!isset($attributes['data-callback'])) {
             $functionName = 'onSubmit' . str_replace(['-', '=', '\'', '"', '<', '>', '`'], '', $formIdentifier);
             $attributes['data-callback'] = $functionName;
-        $attributes = $this->prepareAttributes($attributes);
-
-        $button = sprintf('<button%s><span>%s</span></button>', $this->buildAttributes($attributes), $text);
             $javascript = sprintf(
                 '<script>function %s(){document.getElementById("%s").submit();}</script>',
                 $functionName,
                 $formIdentifier
             );
+        }
+
+        $attributes = $this->prepareAttributes($attributes);
+
+        $button = sprintf('<button%s><span>%s</span></button>', $this->buildAttributes($attributes), $text);
 
         return $button . $javascript;
     }