Sometimes, when you want to send your Tradingview alerts to MT5, after setting up your MT5 Tradingviewtobot, you may face an unknown error 1001. Error 1001 is an internal MQL WebRequest error which means 1001 - SOCKET_HTTP_NO_CONNECTION.
It is a known issue in MT5 but there is no sufficient documentation by the MT5 team. For some reason, a connection between the MT5 server and the EA cannot be established, the Tradingviewtobot keeps sending a retry request every 2 seconds until a successful connection is achieved. So leaving the EA installed and the MT5 instance open for a few minutes will fix this error.
Another known way that seems to fix this issue is to use a VPN if you have the setup on your local PC or to change the source of your internet connection. You can also try on a different PC that is using a different internet connection.
If you are having your setup on a VPS, consider trying it on a different VPS or your local PC. In most cases, it will work on your PC and you would consider having it on a different VPS