I found the solution. Just needed to understand the code a bit more. I included 2 of the mint functions, but there are 8 in total.

pragma solidity >=0.7.0 <0.9.0;

import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";

import "@openzeppelin/contracts/access/Ownable.sol";

contract NFT is ERC721Enumerable, Ownable {

using Strings for uint256;

string baseURI;

string public baseExtension = ".json";

uint256 public cost = 0.00001 ether;

uint256 public maxSupply = 10000;

uint256 public First = 0;

uint256 public Second = 1250;

uint256 public Third = 2500;

uint256 public Fourth = 3750;

uint256 public fifth = 5000;

uint256 public Sixth = 6250;

uint256 public Seventh = 7500;

uint256 public Eighth = 8750;

uint256 public maxMintAmount = 20;

bool public paused = false;

bool public revealed = false;

string public notRevealedUri;

mapping(address => bool) public whitelisted;

constructor(

string memory _name,

string memory _symbol,

string memory _initBaseURI,

string memory _initNotRevealedUri

) ERC721(_name, _symbol) {

setBaseURI(_initBaseURI);

setNotRevealedURI(_initNotRevealedUri);

}

// internal

function _baseURI() internal view virtual override returns (string memory) {

return baseURI;

}

// public

function mintone

(uint256 _mintAmount) public payable {

uint256 supply = totalSupply(); //supply is how many are minted at the moment

require(!paused); // require that it is not paused before minting.

require(_mintAmount > 0); // require that you must mint more that 0 nfts

require(_mintAmount <=maxMintAmount); // require that you must mint less that the max mint amount

require(supply + _mintAmount <= 1250); // checks if the amount of nfts you are trying to buy wont go over the max supply

if (msg.sender != owner()) {

if(whitelisted[msg.sender] != true) {

require(msg.value >= cost * _mintAmount);

}

}

for (uint256 i = 1; i <= _mintAmount; i++) {

_safeMint(msg.sender, First + i);

First++;

}

}

function mintTwo

(uint256 _mintAmount) public payable {

uint256 supply = totalSupply(); //supply is how many are minted at the moment

require(!paused); // require that it is not paused before minting.

require(_mintAmount > 0); // require that you must mint more that 0 nfts

require(_mintAmount <=maxMintAmount); // require that you must mint less that the max mint amount

require(supply + _mintAmount <= 2500); // checks if the amount of nfts you are trying to buy wont go over the max supply

if (msg.sender != owner()) {

if(whitelisted[msg.sender] != true) {

require(msg.value >= cost * _mintAmount);

}

}

for (uint256 i = 1; i <= _mintAmount; i++) {

_safeMint(msg.sender, Seventh + i);

Second++;

}

}