Fixing a ERC721 unchain NFT problem

Job ID: 33361144

Budget: $1,500 – $3,000 USD

I have the following smart contract for ERC721 which I used base64 to embed it on chain.

https://gist.github.com/dr-data/cf3180b5244f4cc2f09d3bdab7973dd7

I can't make this show correctly in opensea. It doesn't validate the asset / metadata according to the tool from opensea: https://testnets-api.opensea.io/asset/0x12DAb9a7211Af3B75381A541adf816A1B328b490/0/validate/?format=api

*I will pay more if you can fix it within 5 hours*