WooCommerce + OceanWp

Hi added more fields to my WooCommerce default registration form with the php code, but the problem is that in my backend, the first and last name text fields I added are not saving the keyed in data. when I check the registered user in my backend, neither the first name or last name displays (they are missing). Below is the code I used.

//add more fields to default registration
//registration fields
function wooc_extra_register_fields() {?>

<p class=”form-row form-row-first”>
<label for=”reg_billing_first_name”><?php _e( ‘First name’, ‘woocommerce’ ); ?><span class=”required”>*</span></label>
<input type=”text” class=”input-text” name=”billing_first_name” id=”reg_billing_first_name” value=”<?php if ( ! empty( $_POST[‘billing_first_name’] ) ) esc_attr_e( $_POST[‘billing_first_name’] ); ?>” />
</p>
<p class=”form-row form-row-last”>
<label for=”reg_billing_last_name”><?php _e( ‘Last name’, ‘woocommerce’ ); ?><span class=”required”>*</span></label>
<input type=”text” class=”input-text” name=”billing_last_name” id=”reg_billing_last_name” value=”<?php if ( ! empty( $_POST[‘billing_last_name’] ) ) esc_attr_e( $_POST[‘billing_last_name’] ); ?>” />
</p>
<div class=”clear”></div>
<?php
}
add_action( ‘woocommerce_register_form_start’, ‘wooc_extra_register_fields’ );