I used part of the "Laundry App UI Kit Sketch Resource" design that was designed by Satheesh Kumar at: https://www.sketchappsources.com/free-source/3397-laundry-app-ui-kit-sketch-freebie-resource.html to create a quick prototype

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A basic mockup of a sign-up/sign in screens along with a 2-way authentication of a uniquely generated code each time.