Dokan add fields on the New Product page

Hi,
So what I’m trying to do is add new custom fields onto the Dokan new-product-single.php, for example a select field from where the vendor can choose the number of external links they allow on their website.

I have already tried adding some simple code like this one:

<div class="dokan-link-number">
	<div class="dokan-input-group">
		<label class="form-label"><?php esc_html_e( 'Number of links you allow', 'dokan-lite' ); ?></label><?php echo get_post_meta( $post->ID, "wccaf_precio_por_", true ); ?></span>
			<div class="dokan-w4">
			<select class="wccaf-field " name="link_number" wccaf-type="select" wccaf-pattern="mandatory" wccaf-mandatory="yes">
				<option value="empty">Select link number:</option>
				<option value="one">1</option>
				<option value="two">2</option>
				<option value="three">3</option>
				<option value="four">4</option>
			</select>
	</div>
</div>

But it doesn’t show up in the product layout the client sees and either it appears on the Products section in the wp-admin.
How could I make custom fields on the new-single-product.php and for them to appear on the admin Products page and the clients’ products layout?