Front-end form not saving data in backend fields

• mars

• March 7, 2020 at 2:25 am

Hi there, i’m using the acf_form() to get some custom field in a create new post page(this page isn’t from ACF), the issue is that i can’t save the fields, so can’t saving the fields I can not even use get_field() dynamically in other pages.
My code in the new post page

 <div class="card-header">
    <?php 

          acf_form();

          $telaio = get_field('vin');

          update_field( 'vin' , $telaio);

          $marca = get_field('marca');

          update_field('marca', $marca);
                                ?>
                            </div> 

My code in the page where i want to display fields values

<p class="informazioni-agg"> <?php echo get_field("vin"); ?>

 <p class="informazioni-agg"> <?php echo get_field("marca"); ?>

Any solutions?
ps: initially this code kinda worked, but echo get_field() always dsplaying “0” i thought because not getting value from frontend but from backend so nothing set and came out 0.