The link is a link to a chat by its username. Call searchPublicChat with the given chat username to process the link. If
the chat is found, open its profile information screen or the chat itself. If draft text isn't empty and the chat is a
private chat with a regular user, then put the draft text in the input field.
Subtype of InternalLinkType.
The link is a link to a chat by its username. Call searchPublicChat with the given chat username to process the link. If the chat is found, open its profile information screen or the chat itself. If draft text isn't empty and the chat is a private chat with a regular user, then put the draft text in the input field. Subtype of InternalLinkType.