hello
go to Customize > Additional CSS > Add Below CSS and publish it then let me know it work or not

@media only screen and (device-width: 768px) {
/* For general iPad layouts */
.single-slide .img-responsive img{
height:430px;
max-height:100%;
object-fit:cover:
}
button-slider.radius.animated.fadeInUp.fadeInDown {
margin-top: 20px;
}
}