This plugin adds a filter action that sends new articles to a webhook for a Discord server channel.
Clone this repository into your plugins.local directory in your TT-RSS installation. Ensure the plugin directory is named EXACTLY discord_webhook, otherwise it won't work.
Once you have enabled the plugin a new section called Discord Webhook should be available in the Preferences tab in your TT-RSS settings where you can enter a webhook URL.
A new filter action should also be available. Select Invoke plugin as the filter action then Discord_Webhook: Send to Discord.