How do I download CA on iOS to send to another device?

I set up my Start9 dashboard on my iPad. It loads at my URL.local on my iPad. However, now I have to get the CA root cert on my other devices. When I click to download the cert on my iPad, it just goes to install and I can’t seem to find the downloaded file. Any clues how I can proceed?

If you want an easy way to download the cert file on each device, use each device to access your unique .local URL. Telling your to download the root CA file will be the first thing you see.