Who do I ask for a reference after a layoff? - 12 months and counting

I worry a reference will only confirm dates of employment. I have read a lot of threads here and could not find my exact situation. A colleague offered to vouch for me. How do you ask politely?

Use a professional network to find a former manager. Many will still write a note.

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