You can change default Prefix with p!setPrefix <new Prefix> or by heading to the dashboard's main settings page.

Simply visit https://bot.dagrate.tk in your browser, then authorize the application.

First, simply fill out the embed that you want, then press on the send button which is located at the bottom right of the page. Once clicked, you will have the option of sending it to a channel of your choice, to save it as a custom command, or send it as a webhook.