How do I get my parents (they are the old get-money-must-spend types) to prepare for retirement and how should they do so?

Hi all,

My parents are the old get-money-must-spend types as they came from poorer backgrounds and made it to good stable salaries. Their kids (me included) have grown up well and can pay for their own futures and now they are rapidly approaching retirement age.

How do I approach them about having to invest for retirement? They seem to reject investments as gambles. Additionally, any advice on 50+ year olds that do not invest? Would parking it all in a robo make more sense than management?