Because Taiwanese government isn't really friendly to Bitcoin, FamilyMart and Bitoex had to get around it.
Instead of walking to a convenience store and purchasing goods with your Bitcoin wallet directly, you need to buy a coupon on Bitoex, print it at the store and give to the cashier. Sounds little complicated, but it's fairly easy.
If you don't have an account on Bitoex yet, make sure to create one.
Give them as little information as possible, your ID verification isn't required for this type of transaction.
Also, make sure you have funds in your wallet.
#1 Open the dashboard of your Bitoex account, click "Coupons" in the left-hand side navigation and choose "Coupons".
#2 NT$100 and NT$200 worth of Bitcoin coupons are available. Choose the desired option and click "Buy".
#3 You will be prompted with a confirmation popup. In my case, it's an OTP (One Time Password) of the 2-way authentication. If you haven't set it up, you should be prompted with a simple confirm button as far as I remember.
#4 Go to your coupon's History page (misspelled as "Histroy" lol) and click the "Show" button of the first transaction.
Take a note of the "Product Serial Number" because you will need it later.
Use the Coupon
Go to any FamilyMart on the island, pick your goods (unfortunately you can't pay for services such as topping up your MRT card etc) and proceed to FamiPort.
It's a machine that lets you print, buy venue tickets, call a taxi etc. You'll use it to print out your coupon.
Please note, that buttons order may be different. I think they reorder it from time to time.
#1 Press the "紅利" button which stands for "Bonus".
#2 Press the "紅利Pin碼". It means "Bonus Pin Code".
#3 Use the right-hand side navigation to get to the 3rd page and click the "Bitoex" button. They may add/remove more services so it may be on a different page.
#4 Fill in your "Product Serial Number" copied from Bitoex website and confirm with the "確認" button.
#5 Accept the Terms. Tick the checkbox and click the blue button next to it.
#6 Check the right value and amount of coupons. Confirm with the "確認" button.
#7 Print the coupon. Just press the big blue button on the right.
#8 Get the coupon, go to the cashier and pay for your goods.
If the price of goods is over your coupon value you can pay the rest with cash.
If the price is lower no change will be returned. Just grab some chewing gums to get as close to the coupon value as possible.
Please let me know in the comments below whether this method worked for you.
You can also share what kind of goods you purchased. I always go for a beer, because beer purchased with Bitcoin always tastes better.