There is 1 error
This voucher is not valid yet
There can be multiple reasons behind this depending on the conditions you defined for the rule.
Please check the validity of the voucher or if you have applied any restriction on room type or customer group.
Also, check how total vouchers and per person vouchers are available.
Still, you face the issue then please raise a ticket.
rather you can as well share the step by step procedure of doing it since i did it as per online tutorials.
Can you please share the screenshot of the error?