The last three digits are part of your computer's IP address on the network. For example, a typical address on a home network might be 192.168.0.132. Every other device on your home network will have differing digits in the last set.
Assuming that you've started the content server, open Safari on your iPhone, then navigate to the calibre server:
Code:
http://192.168.0.132:8080
If you're using
Marvin for iOS, you can browse your calibre library and download books directly from within the app instead of using Safari.
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