You can edit the mint function require the user to transfer certain ERC-20 tokens in your mint function. You can define a price for the ERC-721 tokens in terms of the ERC-20 token, and perform a transferFrom on the ERC-20 contract.

Of course, the user should have to approve the ERC-721 contract as a spender. The code could look something like this.

` contract MyNFT is ERC721 { address tokenAddress; uint256 price;

constructor(address _tokenAddress, uint256 _price) ERC721("MyNFT", "NFT") {
    tokenAddress = _tokenAddress;
    price = _price;
}

function safeMint(address to, uint256 tokenId) public {
    ERC20(tokenAddress).transferFrom(msg.sender, address(this), price);
    _safeMint(to, tokenId);
}

}`

You can edit the mint function require the user to transfer certain ERC-20 tokens in your mint function. You can define a price for the ERC-721 tokens in terms of the ERC-20 token, and perform a transferFrom on the ERC-20 contract.

Of course, the user should have to approve the ERC-721 contract as a spender. The code could look something like this.

` contract MyNFT is ERC721 { address tokenAddress; uint256 price;

constructor(address _tokenAddress, uint256 _price) ERC721("MyNFT", "NFT") {
    tokenAddress = _tokenAddress;
    price = _price;
}

function safeMint(address to, uint256 tokenId) public {
    ERC20(tokenAddress).transferFrom(msg.sender, address(this), price);
    _safeMint(to, tokenId);
}

}`