Mask With Shape in Davinci Resolve (with just two clicks) - Dub'ya Shorts

Disclaimer: I am by no means a video editor - the entirety of my experience in the field comes from making these little vids, which you can plainly see are not exactly feats of advanced craftsmanship 😝 I was trying to find this tip & couldn't, though, so I thought I'd make my own little contribution.