reason=<reason> is optional. Here, you can concisely explain the reason of your proposal.
discussion=<discussion page> is optional. The page where discussion about the move is taking place. For a non-talk page, the matching talk page can have the whole discussion and should have a link to the discussion if elsewhere.
frommessage=<from message> If omitted, the pagename is given. Optionally, the desired message might include a date eg: '...It is proposed that on 2023-02-04, Template:Move, be renamed...'. The bit in the green text would be the desired <from message>.