Layoffs and Reductions in Force My Employer is Laying Me Off but Asking Me to Sign a Resignation Contract

My question involves labor and employment law for the state of: MO
My employer (a non-profit) has told me they want to lay me off for position elimination in next calendar year .
Now they sent me a separation contract indicating that I am resigning and that I am giving up all legal recourses.
Can they do that? Should i request a lay off contract instead and what are the implications? what should I do?
thank you

Layoffs and Reductions in Force My Employer is Laying Me Off but Asking Me to Sign a Resignation Contract