Who do I ask for a reference after a layoff?

I worry a reference will only confirm dates of employment. This is my first time dealing with any of this. 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.

Thanks for writing this out. I went through something close to it 12 months ago, and it settled down once I kept a simple log of every call and form.