Fluent Form alter data before submission

fluent_forms_alter_data_before_submission.php

add_filter('fluentform_insert_response_data', 'your_custom_response_data_filter_function', 10, 3);

function your_custom_response_data_filter_function($formData, $formId, $inputConfigs)
{
   if($formId != 151) {
      return $formData;
   }
	
	$formData['email'] = 'test@gmail.com';


   // Your can alter the data here
    return $formData;
}