The lady giving instructions in this video is a good seamstress but lousy medical care provider. Don't listen to anything she says about flipping masks inside out. But do follow her sewing instructions if you want to make these. It's also very easy to make filters to go inside these out of hepa vacuum bags. My neighbor and I have made almost 100 of these plus...I really don't know how many filters...a lot...so that every employee at my daughter's work can have two. She works in a medical facility which ran out of masks last week, and were unable to order any more, so until they got donated homemade ones they literally had nothing. Her brother in law is an ER physician in another state and in his hospital the protocol for who gets masks, how long they wear them, etc, are ridiculous, but she has sent a stack of homemade ones, which he uses as a cover for an n-95. Changes the cover with every patient, but and replaces the n-95 underneath as often as he can according to his hospital's protocol. Washes the covers every day in HOT water with bleach. Ideal? No way. Better than nothing? Absolutely yes. At dear daughter's facility they're also using tight fitting protective goggles (like lab goggles) from Home Depot to keep the edges of the mask tight against their faces and provide some eye protection.

Finally, here's a link to help you get ppe to professionals who need them. Most prefer the fitted type from above over the rectangular pleated ones, but will take anything since anything is better than nothing.