dont load all iFrames in Owl Carousel same time - html

Question

I have a website with 3 iFrames in a Owl Carousel slider. It needs a lot of performance because it loads 3D-CGI content I need to show. A single iFrame is loaded in some seconds which is okay, but it loads all 3 iFrames at the same time and this will cause very long loading time and some older smartphones cant handle it.
How do I make it to stop load all 3 iFrames togheter and load every single when its viewed instead?
JsFiddle
$('.carousel2').owlCarousel({
loop:true,
autoplay:false,
dotsEach: false,
responsiveClass:true,
mouseDraggable: false,
navText : ['<i class="fa fa-angle-left" aria-hidden="true"></i>','<i class="fa fa-angle-right" aria-hidden="true"></i>'],
responsive:{
0:{
items:1,
margin: 10,
dots:true,
nav:true,
loop:true
},
600:{
items:1,
nav:true,
dots:true,
margin: 100,
loop:true
},
1000:{
items:1,
margin: 100,
dots:true,
nav:true,
loop:true
}
}
})
// On Scroll:
// Change Header from Transparent to white and back and from absolute to fixed
window.onscroll = function() {
// Change iframe data-src to src to render it when its in view
// && window.matchMedia("(min-width: 680px)").matches
if ( window.pageYOffset > 150 ) {
var iframe1=$('.myIframe1');
var iframe2=$('.myIframe2');
var iframe3=$('.myIframe3');
if (iframe1.data('src')){
iframe1.prop('src', iframe1.data('src')).data('src', false);
}
if (iframe2.data('src')){
iframe2.prop('src', iframe2.data('src')).data('src', false);
}
if (iframe3.data('src')){
iframe3.prop('src', iframe3.data('src')).data('src', false);
}
}
}
.space {
height: 200px;
}
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/OwlCarousel2/2.3.4/assets/owl.carousel.css" integrity="sha512-UTNP5BXLIptsaj5WdKFrkFov94lDx+eBvbKyoe1YAfjeRPC+gT5kyZ10kOHCfNZqEui1sxmqvodNUx3KbuYI/A==" crossorigin="anonymous" referrerpolicy="no-referrer" />
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/OwlCarousel2/2.3.4/assets/owl.theme.default.css" integrity="sha512-OTcub78R3msOCtY3Tc6FzeDJ8N9qvQn1Ph49ou13xgA9VsH9+LRxoFU6EqLhW4+PKRfU+/HReXmSZXHEkpYoOA==" crossorigin="anonymous" referrerpolicy="no-referrer" />
<div class="space"></div>
<div class="interactive_desktop">
<div class="carousel2 owl-carousel owl-theme">
<div class="item products_3_img">
<iframe class="myIframe1" style="width: 800px; height: 800px;" src="about:blank" data-src="https://de.wikipedia.org/wiki/Wikipedia:Hauptseite" ></iframe>
</div>
<div class="item products_3_img">
<iframe class="myIframe2" style="width: 800px; height: 800px;" src="about:blank" data-src="https://de.wikipedia.org/wiki/Portal:Wikipedia_nach_Themen"></iframe>
</div>
<div class="item products_3_img">
<iframe class="myIframe3" style="width: 800px; height: 800px;" src="about:blank" data-src="https://de.wikipedia.org/w/index.php?title=Portal:Wikipedia_nach_Themen&oldid=212000847"></iframe>
</div>
</div>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/OwlCarousel2/2.3.4/owl.carousel.js" integrity="sha512-gY25nC63ddE0LcLPhxUJGFxa2GoIyA5FLym4UJqHDEMHjp8RET6Zn/SHo1sltt3WuVtqfyxECP38/daUc/WVEA==" crossorigin="anonymous" referrerpolicy="no-referrer"></script>

Answer 1

Theres an option for owl carousel to activate lazyload.
$('.owl-carousel').owlCarousel({
items:4,
lazyLoad:true,
loop:true,
margin:10
});