Don't do it. Seriously.
Although we don't allow the editing of your NFT within the Single app after the release date has passed, we can't prevent you from making some edits within Shopify directly, specifically the total supply and price. However, we HIGHLY suggest you refrain from doing so. Here are some reasons why:
First and most importantly, changing the quantity for your NFT within Shopify will result in an inaccurate total supply number and lead to the release being invalidated and devalued. You will see issues such as NFTs being labeled as edition #50/30, amongst other things.
We cannot fix this issue and do not take liability for any other resulting problems if you edit your NFT quantity in Shopify.
On top of the fact that changing the quantity in Shopify will essentially "break" your NFT release, consider this: when fans purchase your NFTs, they are doing so with the scarcity you have already defined in mind. If you change the total supply, that changes the rarity of the NFT as well, and affects the legitimacy of the collection as a whole. Think about it like this: You purchased a collectable that was marketed as only having 100 made. You now have 1 out of only 100 that will ever exist. Cool! However, after doing so, you later find out that the seller decided to actually release 500 instead. That collectable suddenly just got a lot less rare and you're likely a little less than happy with the seller.
The same thing goes with changing the pricing of an NFT after it has been released. For example, if you charge $30 for the first 250 out of 500 that you sell, but then decided to charge $20 for the other 250 of the total supply, that will have an impact on the overall value of the NFT. Plus, it is likely to cause the fans who purchased at $30 to feel a bit disappointed.
Additionally, altering the supply or price after the release of an NFT will generally affect its value on the secondary market, typically in an undesirable way. This will impact the royalties you receive from subsequent sales on the secondary market, which can mean less profit for you.
So in summary, DO NOT CHANGE THE QUANTITY OR PRICE OF YOUR NFT IN SHOPIFY. Not only will it result in unfixable errors and the devaluation/invalidation of your release, but on top of that...it's just not cool.
Note: The issue of changing price from within Shopify does not refer to discount codes or coupons. Providing discount codes or coupons that reduce the price of an NFT at time of checkout is completely acceptable and will not cause any problems.