Specifying the username and/or hostname for checkouts is particularly useful when all checkouts occur from the same machine, but you want to do user-specific checkouts. To set the username and hostname, you use LMX_OPT_CUSTOM_USERNAME and LMX_OPT_CUSTOM_HOSTNAME, respectively, as described in LMX_SetOption.
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You can override this behavior by specifying a custom username and hostname that is unique for all sessions, just like a normal user account. This will result in a license being consumed by a unique user every time a client logs in from a browser.
The LMX_OPT_CUSTOM_USERNAME and LMX_OPT_CUSTOM_HOSTNAME options can be set only once. If you try to set them more than once, you will get the error LMX_INVALID_PARAMETER. If you need to use multiple usernames/hostnames inside one application, you must use separate LM-X clients.