Members

The member command allows you to configure member join and leave messages. There is a limit of 3 join messages and 3 leave messages. You can configure them to be sent in a server channel (Guild type) or in user's direct messages (Direct Message type). You can fully customize the message's content, embeds, allowed mentions and flags. Support for message components will be coming later.
Currently editing member messages on website's dashboard is disabled until it gets fully finished.

Placeholders

Placeholders can be used to insert dynamic content into the message, such as the user's username or ID. They are represented as %%PlaceholderName%%.
Discord's API has limitations on length of certain properties in messages, which you can see here. For example, message content is limited to 2000 characters. When you use placeholders, keep these limitations in mind to ensure your messages are sent successfully. As an example, let's say your message content has 1990 characters and you then add %%userid%% to it. While you might think everything will be fine as the content should have exactly 2000 characters now, after the placeholder is resolved it will in fact exceed the limit as Discord Snowflakes have at least 17 characters.
Placeholders have unique types allowing them to be used as helpers in some contexts. Here is a list of them:

• String
• Number
• URL (useful for image URLs)
• ISO Date (useful for embed timestamps)
• Timestamp (useful for timestamp message formatting)
• Color (can be used only for embed color field)
  Here is a list of available placeholders:
• guildbannerurl (URL)
• guildiconurl (URL)
• guildid (String)
• guildmembercount (Number)
• guildname (String)
• nowdate (ISO Date)
• nowtimestamp (Timestamp)
• useravatarurl (URL)
• usercreateddate (ISO Date)
• usercreatedtimestamp (Timestamp)
• userdisplayname (String)
• userglobalname (String)
• userid (String)
• userjoineddate (ISO Date)
• userjoinedtimestamp (Timestamp)
• usermention (String)
• username (String)
• guildiconcolor (Color)
• useravatarcolor (Color)