How to randomly pair bundles without code module?

we have bundles that look like this:
[
{ “email”: “emial1@gmailcom”, “username”: “Ramona Schwab” },
{ “email”: “email2@gmailcom”, “username”: “Horst Fuchs” },
{ “email”: “hr@gmailcom”, “username”: “Kira Erpenbach” },
{ “email”: “email3@gmailcom”, “username”: “Jeremy Richter” },
// … up to 19 members
]

and I’m confused about how to create pairs so it look like this:

{
“pairs”: [
[
{ “email”: “ramona.schwab@gmail.com”, “username”: “Ramona Schwab” },
{ “email”: “horst.fuchs@gmail.com”, “username”: “Horst Fuchs” }
],
[
{ “email”: “hr@gmail.com”, “username”: “Kira Erpenbach” },
{ “email”: “jeremy.richter@gmailcom”, “username”: “Jeremy Richter” }
],
// … more pairs
],
“unpaired”: // or [{ “email”: “…”, “username”: “…” }] if odd
}

I tried the iteration through pairs, but even with detailed explanation from llm I still fail to make it work.

Any ideas?