References when my manager was laid off too, recruiter here

The company closed and I am not sure how to reach former colleagues. I have read a lot of threads here and could not find my exact situation. A colleague offered to vouch for me. Who did you use?

Ask former colleagues and supervisors in a short message and give them a summary of the job you are applying for.

A client reference worked well for me. It shows you deliver outside the company too.