How to make a USDT TRC20 transfer using a private key?

Question

I want to find out how you can send TRC-20 with a private key. In the documentation, I found a method for creating a smart contract. But I can't figure out how to get "owner_address" and "contract_address"

import requests

url = "https://api.shasta.trongrid.io/wallet/triggersmartcontract"

payload = {
    "owner_address": "41D1E7A6BC354106CB410E65FF8B181C600FF14292",
    "contract_address": "41a7837ce56da0cbb28f30bcd5bff01d4fe7e4c6e3",
    "function_selector": "transfer(address,uint256)",
    "call_value": 0
}
headers = {
    "accept": "application/json",
    "content-type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)