How to modify code for multiple image upload on product page?

[Zivos]

Hello,

I need on my store image upload because I do print on demand personalised prducts. I added code from internet where I can as a coustomer add picutres which I want on the product. My problem is that I can choose multiple photos, but only one is saved and I can only see one in the orders page. Can someone help me to make it so all the photos client add will be shown? 

My code: 

<div class="product-form__input">
<label class="form__label">*Vyberte své fotky (Maximálně 6 fotek)</label>
<input type="file" form="{{ 'product-form-' | append: section.id }}" name="properties[*Vyberte své fotky (Maximálně 6 fotek)]" required accept="image/*" multiple>
<script>
document.addEventListener("DOMContentLoaded", () => {
document.querySelector("form[novalidate]").removeAttribute("novalidate");
<div class="product-form__input">
<label class="form__label">*Vyberte své fotky (Maximálně 6 fotek)</label>
<input type="file" form="{{ 'product-form-' | append: section.id }}" name="properties[*Vyberte své fotky (Maximálně 6 fotek)]" required multiple>
<script>
document.addEventListener("DOMContentLoaded", ()=>{document.querySelector("form[novalidate]").removeAttribute("novalidate")})
</script>
</div>