Who called from 2092642621

Left message that a lawsuit had been filed against me.

This number just called me. I did not answer. No voice messages were left.

how do you know its a scam

Debt is a civil matter, not a criminal matter.
Scammers love to call out of the blue and say all sorts of illegal threats and give out fake case numbers.
The FDCPA requires debt collectors to notify you five days after the initial call by U.S. MAIL, not by email or text, but by MAIL.
After that, you have thirty days to dispute the debt.

True. I had one who called me and gave a case number, Tues out several other people has the same case number. WTH!