Create captive portal voucher codes as non admin

Hi guys,
we deploy some of APU boards with IPfire to our customers. Many of them use Wi-Fi on blue with captive portal. But they(and me) don’t want call me every time when voucher codes are running low/out to recreate some new.
One solution is to give them the admin credentials BUT i think that this is no good idea.
What could I do to make this more practicable for our customers?
I would prefer an one click link solution.