fotograp template - slide duration carousel

Hello everyone! I need help with my website template. It is based in fotograp template. I’d like to change 5 seg. default slide duration, but I don’t know how can I do it… This is the part of the code:

<div class=“py-5 site-block-testimonial” style=“background-image: url(‘images/cabeceras/cabeceraBN3.jpg’);” data-stellar-background-ratio=“0.5”>
<div class=“container”>
<div class=“row block-13 mb-5”>
<div class=“col-md-12 text-center” data-aos=“fade”>
<div class=“nonloop-block-13 owl-carousel” >

Have I to modificate bootstrap.css, style.css, owl.carousel.min.css code?
Thank you and sorry for my english…

Good morning

thank you for the question
You cant change this property from the css files, check it in the .js files