Short translation/quotation help

Hello, I need help with translating this short dialogue-

Quote: Say "Bye-bye!"

Explanation: A character telling another group of characters to say goodbye to the person leaving. If there's a similar cutesy way of saying goodbye in Japanese that would be perfect, but if not a standard goodbye would be fine.

Second, correct me if I'm wrong, but when a character has quoted text in a manga for example, it would be like: Say [bye-bye!] with some sort of brackets (where we would use quotation marks "" in English?)

Thank you in advance for any help.

Is there any more context? Are they Japanese? Are they teens? Why would they tell somebody else to say "bye"? Is it translated dialog or is the original meant to be in Japanese?

This is a quote from an English game show, where the host (female) is telling the remaining contestants to say goodbye to the player who has been eliminated and is leaving. They are all of adult age.

So the quote is originally in English, but am looking to use it in Japanese.

I'd probably say バイバイって言って, "bai-bai-tte itte" which is a casual colloquial way to say バイバイ(or whatever you want them to say)と言ってください, bai-bai to itte kudasai.

I'd probably go less literal and say お別れの挨拶を言いましょう which sounds a little more natural to me.
(Trans.: "Let's say [our] farewell")