Getting references after a company closes after 5 years as a software tester

My manager was laid off too and I am unsure who to use as a reference. I worked as a software tester before this. I have one former client who liked my work. Who did you use?

I kept a note of my results so my references could be specific. They appreciated it.

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