Getting references after a company closes - 12 months and counting

My manager was laid off too and I am unsure who to use as a reference. I have read a lot of threads here and could not find my exact situation. HR only confirms titles and dates. How do you ask politely?

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

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