Severance offer, what should I ask for? after 15 years as a machine operator

The company sent a severance agreement with a release of claims, and I am unsure what to do. I worked as a machine operator before this. I do not want to leave money on the table. Did anyone negotiate and succeed?

Keep everything in writing and save the confirmation numbers. It saved me later.

Ask for the offer in writing and do not sign on the spot. A day or two to think is normal.