What advice would you give to a 50 year old who hasn’t saved or invested anything their whole life?

This is not the case for me, but what should people do who are nearing the standard retirement age if they’ve saved nothing thus far?

Does it make sense to save in a three fund bogle style portfolio if you’re only 15 or so years out? Should one primarily invest in bonds?

It’s hard to think of how I’d instruct someone in this situation if they came to me for help.