Please be warned that Discord banned ROBLOX IP addresses because people are using it as a logging service, which it isn’t. If you plan to use this to log things that happen within the game, please find another service to use. Otherwise, you can follow the instructions below:
Discord Webhooks use a REST API, which you can use in conjunction with the HttpService to post messages through webhooks. You can find the documentation for it here. You can use the function :PostAsync() and post it through your proxied webhook link. You can also find the parameters to use within the function here. You can also find the Discord Webhook API for posting messages and content. In this case where you want to send a message, you would send the actual message in the content field. Webhook API.