Go to Admin>Shop Settings>Enforced Coupon=YES
Now we can create a New Discount Coupon in Admin>Orders>Vouchers and Coupons
We can make the discount zero
Don’t forget to enable Discount Coupons for the Orders Totals
Now at checkout a customer is asked to provide a Valid Coupon Code
Those with a valid coupon code can now checkout and purchase their tickets as priority
When you want to open up to the public set Enforced Coupon =NO