HELLO, my name is Riquelme and I'm from Brazil. I hope to help many with this guide.
Let's start. To achieve this, I used a solution with Construct3's Ajax calls and a database. Make sure to take all precautions with security.
First, you'll need to create a database and implement a login and registration area for users, or use the Metamask plugin in Construct3.
Store the information in the database, such as user and password, or Metamask if preferred. For this part, you'll need to make an Ajax call to a PHP file passing the data.
Keep in mind that all the web3 part stays on the website, this is the same solution as other projects done in other engines.
You'll need to have a website linked to the same database for users to log in, etc., and the web3 part.
If you create a token for your game, you need to send its balance information through Construct3 to the database. On the website, you can create a section for the user with a wallet, connect it with Metamask for withdrawals. If you want automatic payment, create a smart contract in Ethereum's Remix IDE.
For all interactions with the smart contract, you'll need to use web3.js and, depending on your Blockchain, use Infura.
You can also use manual payments.
NFTs: This part is simple. First, you'll need to create an NFT. You can use sites like Minite that make this process fast.
Create a section for the user to link their NFT, or if desired, create a smart contract for the user to lock their NFTs.
If you use services like OpenSea for NFTs, you can check if the user's wallet has the NFT via API. However, I still suggest locking the NFT.
Once the user locks the NFT, the system needs to record something in the database.
For example: Joãonft3
Again, with Ajax, you'll need to send this information to Construct3.
Store the information in a global variable.
Do something like if the player has "Joãonft3" in variable x, release the character "João", which is the NFT.
"I suggest that when the user logs in, make several AjaxLast.data events to quickly store all the information in global variables.
This was just a quick tutorial to show you the way. If you have any questions, I can answer. 🙏❤️
It's a bit convoluted because there's a lot to cover.