These are no longer my favorites because there is no pocket for a filter!!! Check out my other two posts for masks.
Surgical Masks to Make
This one from Joann’s Fabric
https://www.youtube.com/watch?v=VgHrnS6n4iA
or these look pretty good and the pattern is in 4 sizes:
https://www.lisascarolina.com/2019/02/fabric-face-masks-easy-but-fiddly-and.html
https://www.craftpassion.com/wp-content/uploads/2013/08/face-mask-pattern-1.pdf