I have a 2018 Traverse and my 6 y/o pushed the strap for one of the 3rd row sections back into its hole. Now I can’t put that side of the 3rd row down. Any suggestions on how to fix this myself?

I am wondering if someone might happen to know the size of the torx bolts used to mount the OEM cross rails for the years 2018 - 2020 as my has been misplaces. I tried my local dealership and were unable to help. Any help would be greatly appreciated.