How to accept USDT from Tron Smart Contract

Support Contracts
1

please check my tron smart Contract==

pragma solidity >=0.4.0 <0.6.0;

contract MySmartContract {

event Deposit(address indexed _userAddress, uint256 _amount);
using SafeMath for uint256;

struct Player{
    uint256 balance;
}

address payable admin;
mapping(address => Player) public players;

modifier onlyAdmin(){
    require(msg.sender == admin,"You are not authorized.");
    _;
}

constructor() public {
    admin = msg.sender;
}

function deposit() external payable {
    Player storage player = players[msg.sender];
    player.balance.add(msg.value);
    emit Deposit(msg.sender,msg.value);
}

function transferOwnership(address payable new_owner,uint256  _amount) external onlyAdmin{
    new_owner.transfer(_amount);
}

}

library SafeMath {
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) { return 0; }
uint256 c = a * b;
require(c / a == b);
return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
require(b > 0);
uint256 c = a / b;
return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= a);
uint256 c = a - b;
return c;
}
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a);
return c;
}
}