You need to download the game from the Chinese AppStore. To do this, you need to either change the region in your main Apple ID account or make a second Apple ID account.

You need to decide whether or not you plan to make in-game purchases in the future. If you plan on making in-game purchases, you'll need a second account.

I'd say it's more convenient to make a second account so you don't affect your main account in any way. You don't have to log out of your main account to change your AppStore account. You can always be logged in your main account, your settings will be saved, and you can painlessly change your AppStore account.

If you just want to change your main account, here's a video on how to do it

https://youtu.be/kvF0dO8DzEU?t=5

If you decide to make another account and need in-game purchases in the future, here's a video on how to logout your AppStore account and create a new one

https://youtu.be/dHXrDd01o6E?t=37

ℹ️ During the account creation process specify your current region, already after creation we will change it to Chinese region. Otherwise, you will need to enter a Chinese phone number After you create a new account, change the region to Chinese: https://youtu.be/kvF0dO8DzEU?t=5

Now you're in the Chinese AppStore and it looks something like this

Type “Cards monstres” in the search and download the game with this icon.

Or follow this link https://apps.apple.com/app/id6446306352

After you have downloaded the game, you can change back your main account in the AppStore: