Frame tie-down points?
I use the J shaped one here:
https://www.ebay.com/itm/4-RTJ-Clust...BWH-kp&vxp=mtr
Alternatively (i have these also), you can just buy these and loop around whatever under the car.
https://www.ebay.com/itm/4-36-HD-Axl...dRcjME&vxp=mtr
I prefer the hooks though. The holes for the hooks are here:









