WebFlow's CMS supports video fields, however there are currently [ Nov 2018 ] two key limitations;
Fortunately, there is a way around both of these limitations.
Note that if you are using Zapier, you want to...
To make your embed responsive, maximizing video width while preserving the aspect ratio, we've used the technique in this article...
Example HTML construction;
frameborder="0" allowfullscreen class="video"></iframe>