mitmproxy/doc-src/certinstall/webapp.html

By far the easiest way to install the mitmproxy certs is to use the built-in
web app. To do this, start mitmproxy and configure your target device with the
correct proxy settings. Now start a browser on the device, and visit the magic
domain **mitm.it**. You should see something like this:

<img src="@!urlTo("webapp.png")!@"></img>

Just click on the relevant icon, and then follow the setup instructions
for the platform you're on.