Bolt for hitch carrier crossmember

[nicolas2b54]

Hi all,

I remove my hitch carrier crossmember several years ago, and I lost the hardware (bolt, nuts). Do you know which size and grade I need ? Is there a toyota reference for that ?
I looked in the part list on PartSouq but did not find this exact part. Only the general area (frame, rear crossmember).

Thanks for your help