How to superimpose a transparent clip (with no alpha) ?

Hello, I am triyng to create a rain effect over a landscape video. I found a MP4 video clip on a image bank with raindrops over a transparent background with no alpha. I downloaded a test copy to try it on my video. When I add it to a timeline over the landscape clip I still see the white an black chess like background  No transparency. How do I get to see only the raindrops? Is there an effect or a way to do this? Thanks for any help. I attach the test clip