how to deal with bootstrap 4 carousel images different sizes code example

Example 1: size carousel bootstrap 4

.carousel .item {
  height: 300px;
}

.item img {
    position: absolute;
    top: 0;
    left: 0;
    min-height: 300px;
}

Example 2: bootstrap 4 carousel image problem

Check if your images folder is on wwwroot. Otherwise when the page is loaded it wont read the files.