The short answer
Ask directly, once, soon after the experience, and make it one tap. The most effective request is short, specific to what you just did for them, and carries a link straight to the review box.
The rules differ by platform, and that matters more than the wording.
What to say
Short. Name the thing you did, ask plainly, give the link. “Thanks for having us in today — if you have a minute, a review helps other people find us: [link]”. That is the whole message.
Do not suggest what to write, do not ask for five stars, do not apologise for asking. Suggesting content is what turns a review into something the reader can smell.
When and where
Same day, in the channel you already use with that customer — the confirmation email, the thread you were messaging in, a card at the end of the job. A dedicated review-request email from an address they do not recognise performs worse than a line in a message they were expecting.
