From the documentation, you can just create (or delete) one visitor/guest per API call:

Also, in JSON you can't just concatenate multiple JSONs like you do (. { json1 }{ json2 } ); it would be more like [ { json1 },{ json2 } ]; but I'd expect it still not to work as the documentation only shows the model for a single guest user. With some python (or other) script, it's trivial to split up your accounts to multiple API calls with one account at a time.
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Herman Robers
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If you have urgent issues, always contact your Aruba partner, distributor, or Aruba TAC Support. Check
https://www.arubanetworks.com/support-services/contact-support/ for how to contact Aruba TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
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