Want to use a form to process a voucher verification code and save the result and code

Hi,

Hoping for some help please. I want to execute this code within a formidable form. How can I do this? Any help will be appreciated. Tks

<div class="white-block">
<div class="white-block-content">
<form method="post">
<p><?php esc_html_e( 'In order to check for voucher input it into the field bellow and click on Verify', 'couponxxl' ) ?></p>
<div class="input-group">
<label for="voucher_code"><?php esc_html_e( 'Voucher Code', 'couponxxl' ); ?> <span class="required">*</span></label>
<input type="text" name="voucher_code" id="voucher_code" class="form-control" data-validation="required" data-error="<?php _e( 'Please input voucher code', 'couponxxl' ); ?>" value="">
<i class="pline-magnifier"></i>
</div>
<a href="javascript:;" class="btn submit-form ajax-return">
<?php esc_html_e( 'Verify', 'couponxxl' ); ?>
</a>
<input type="hidden" name="action" value="verify_voucher">
<input type="hidden" name="vendor_id" value="<?php echo esc_attr( $vendor_id ) ?>">
<div class="ajax-response"></div>
</form>
</div>
</div>