Hello, please tell me, I will correctly insert the USDC and Cerve contracts into my contract, for some reason they are not picked up


//SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;

import '@openzeppelin/contracts/token/ERC20/IERC20.sol';
import '@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol';
import './interfaces/ICurveAavePool.sol';

contract Main {
address constant internal usdcAddr = 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48;
bytes32 constant internal usdcTicker = 'usdc';

address constant internal aavePool = 0xbEbc44782C7dB0a1A60Cb6fe97d0b483032FF1C7;
using SafeERC20 for IERC20;
ICurveAavePool curveAavePool;

struct Token {
bytes32 ticker;
IERC20 token;
}

mapping(bytes32 => Token) public stableCoins;
mapping(address => mapping(bytes32 => uint)) public depositerBalances;

uint public balanceBefore;
uint public balanceAfter;
uint public depositAmount;

constructor() {
stableCoins[usdcTicker] = Token(usdcTicker, IERC20(usdcAddr));
}

fallback () external payable {}

function deposit(address _depositer, uint _amount, bytes32 _ticker)
payable external validTokens(_ticker) {
depositerBalances[_depositer][_ticker] += _amount;
IERC20(usdcAddr).safeApprove(aavePool, 0);
IERC20(usdcAddr).safeApprove(aavePool, _amount);

uint[3] memory coinAmounts;
coinAmounts[0] = 0;
coinAmounts[1] = _amount;
coinAmounts[2] = 0;

ICurveAavePool(aavePool).add_liquidity(coinAmounts, 0, true);
}