I tried to find a link to which phones are supported for this OS. The closest match I found was a Check Device Compatibility button. It takes me to a page at /installer. In Firefox, I got this:

    Your navigator is not supported.
    WebUSB support is required, you can use the following browsers:
    Microsoft Edge, Opera, Chrome

    Connect your phone to your computer with a USB cable. 
    We will automatically detect your phone to install /e/OS.

I did eventually find the list: https://doc.e.foundation/devices