makeshift squat hooks?

My gym has 2 power racks, each with 2 safety bars. I squat outside of
the rack using the ends of the safety bars to unrack the barbell. If
I fail, there's no protection. I work out alone. This is why I
squat with light weights.

I was willing to purchase squat hooks for the rack, but I've learned
that these racks are 20-25 years old and no hooks on the market will
work with them.

I wonder whether there's a makeshift solution for this problem.

I know. Join another gym (possibility but a lot more money) or buy a
power rack for my home (impossible due to lack of room).