Similar to the Solar Eclipse Viewer goggles I designed (https://makerworld.com/en/models/244735#profileId-261208) I designed some lens filters for my Canon EF-S 18-55mm with IS that make use of the lens from a cheap pair of cardboard solar eclipse glasses.
The two parts are “friction fit”, however a dab of super glue wouldn't hurt to sandwich the filter in place so it doesn't move. The whole filter assembly is a friction fit right over the end of the Canon lens.
I also design a slightly altered version for the Canon EF-S 55-250mm with IS Lens and added it here to Makerworld (https://makerworld.com/en/models/411489#profileId-313412).
Fingers crossed for clear skies on April 8th!