Hover Image > Play Video

#1. First, you add a Video Block with Custom Featured Image.

And make sure these options are enabled.

If you want to disable the Play icon in the middle of the image, disable this option.

#2. Use this code to Custom CSS box

div.video-block video {
    opacity: 0;
}
div.video-block .plyr__poster {
    opacity: 1;
}
div.video-block:hover video {
    opacity: 1;
}
div.video-block:hover .plyr__poster {
    opacity: 0;
}