Hi @Proteu5,
I suggest verifying your token on Etherscan (so that people can easily call functions):
I used Remix to interact with your contract as an ERC721.
Your baseURI looks incorrect: https://hashdeck2.herokuapp.com/api/token/1
Which results in a tokenURI for tokenID 1 of: https://hashdeck2.herokuapp.com/api/token/11
If you have problems with OpenSea, you can ask in their Discord, they are super helpful: https://discord.com/invite/ga8EJbv