This plugin contains many issues.
First of all, it does not support any placeholders besides %player%.
It does require a permission which is not properly documented I believe.
And the worst issue is permission elevation. Any user that can create a voucher can execute any command.
I would advise against using this on your servers.

You asked for a review in the discord, here it is.

i'ts very good plugin, the creator is the best. i want more plugin like these savshdva