Structured data not working right with CSS selectors (adding slashes in links and other problems). How do I fix this? - html

Question

I work for a website with 10000+ products and I decided to input the structured data dynamically via CSS selectors in GTM because doing it manually would be too time consuming. It all worked fine, but then I ran into some problems.
Firstly, the structured data added slashes to links that lead to a 404, like so:
"url": "https:\/\/example.com\/shop\/category\/subcategory\/product"
Secondly, the prices in my country are separated with a comma, and not a dot, so the rich results test returns an error. Is there a way to change this?
Full schema here.
<script type="application/ld+json"> {
"#context": "https://www.schema.org",
"#type": "product",
"sku": "{{sku}}",
"image": ["{{carousel-item active}}"],
"name": "{{product-title}}",
"description": "{{product-description}}",
"category": "{{category}}",
"brand": {
"#type": "brand",
"name": "BRAND",
"logo": "https://example.com/images/logo.png"
},
"offers": {
"#type": "Offer",
"itemCondition": "http://schema.org/NewCondition",
"availability": "http://schema.org/InStock",
"price": "{{price}}",
"priceValidUntil": "2021-11-11",
"priceCurrency": "HRK",
"url": "{{Page URL}}",
"shippingDetails": {
"#type": "OfferShippingDetails",
"shippingRate": {
"#type": "MonetaryAmount",
"value": "25",
"currency": "HRK"
},
"shippingDestination": {
"#type": "DefinedRegion",
"addressCountry": "HR"
},
"deliveryTime": {
"#type": "ShippingDeliveryTime",
"transitTime": {
"#type": "QuantitativeValue",
"minValue": "3",
"maxValue": "5"
},
"cutOffTime": "17:00-08:00",
"businessDays": {
"#type": "OpeningHoursSpecification",
"dayOfWeek": [
"https://schema.org/Monday",
"https://schema.org/Tuesday",
"https://schema.org/Wednesday",
"https://schema.org/Thursday",
"https://schema.org/Friday" ]
}
}
}
}
}
}
</script>
I am very new to this, so please be gentle.
P.S. All other parts of schema work fine.