Prerequisites Before we begin, make sure you have the following:

A development environment for writing and deploying smart contracts, such as Remix, . An Ethereum wallet or an account on a testnet, such as Ropsten or Rinkeby.

1. copy and paste teh factory.sol into remix
2. Compile the smart contracts using a Solidity compiler
3. Deploy the contract using metamask
4. during nft minting, tokenUri is https link of the json file consisting data related to NFT

in the contract, owner is allowed to add admin and create & deploy ERC721 admin is allow to mint NFT and assign it to minter using mintNft function owner of NFT can upgrade the NFT by paying fees

you can send the transaction using mintNFT() in index.js

I have deployed the contract on BSC testnet and the contract address is 0x87aaa7eA6bbfe783f531496055Da2483f6f02E09