I can't get this to work on my iPhone. When I visit mitm.it from my phone, or any other device, it redirects me to grit.io. How do I install the CA. I have the

I can't get this to work on my iPhone. When I visit mitm.it from my phone, or any other device, it redirects me to grit.io. How do I install the CA. I have the proxy up and running on my Macbook pro.