Originally Posted by
CPH-Flyer
There is no way to use them online. I have tried to book a ticket online, not issuing it, and then go by the JAL Plaza in Yurakucho to have the coupons applied. That also triggered the 5300 yen booking fee.
FYI.
If you pay with JAL travel coupons(not JAL coupons) partially, 5400 JPY handling fee is waived.
Reference(as usual, in Japanese)
https://www.jal.co.jp/jcfm/goods/