item class security mass upload

Summary:

Hi Guru,

is there anyway to mass upload the items class security to all the inventory orgs at user or job role level, there are over 1400 inventory orgs in our instance, it's not going to be possible to add them one by one.

I also tried to use the VBCS for this REST API:

But I just got stuck here and dont know how to continue, could you please kindly provide some guidance:

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