How do I ask my users if I can mine cryptocurrency on their browser?

As ridiculous as this question sounds, this is the only place out of all stackexchange websites that made sense. Let's say I have a website and I intend to use the user's browser to mine. I don't want to run hidden scripts and ruin things for the user because I am such a nice guy. How do I design a UX that asks the person to enable/disable in-browser cryptocurrency mining. Thanks for the suggestions in advance