There are many ways to wake your OctoBot up and make it do something, one of them is using a webhook. With a webhook, you can automatically send messages to your OctoBot from any website supporting this system. https://www.tradingview.com is one of them.
In order to be able to receive the webhook's message, OctoBot has to expose an API to the web, for this it uses https://ngrok.com/ that acts as a secure intermediary between the internet and your OctoBot.
Setting up your OctoBot's webhook
In OctoBot configuration, add the webhook service.
To set up your webhook configuration
Option 1: If your OctoBot is not exposed to the Internet you have to :
You can use ngrok with a free account, the only drawback of having a free version is that your webhook address will change at every OctoBot restart, you will have to update it on your message sender (like https://www.tradingview.com)