A friend just send me these two photos of a park meter in Verdun with instructions posted on it to pay by SMS.
Apparently you should first push the “smart” yellow button and text the machine number by SMS to 1315, then push the green button and wait for the receipt. However, there’s no option to choose your parking duration and you will be automatically billed 1,500L.L for 1 hour instead of the usual 1,000L.L, and the instructions do not mention whether the SMS is free of charge or there is any additional cost for it.