When printing with AirPrint, you must configure SSL communication. Follow the procedure below, check the status of the device certificate, and enable SSL communication.
Log in to Web Image Monitor in administrator mode.
Click [Configuration] in [Device Management].
Click [Device Certificate] in “Security“.
Check the status of "Certificate 1" as follows.
Confirm that "Certificate Status" is set to "Installed".
Check "Validity Period" and confirm that the certificate is unexpired.
Click [OK].
Click [SSL/TLS] in “Security“.
Check whether the following items are set to [Active].
Either "IPv4" or "IPv6" in "SSL/TLS"
"TLS1.2" in "SSL/TLS Version"
Click [OK].
Click [Logout].
Quit Web Image Monitor.