There is as well a nice article on Sage city here: https://www.sagecity.com/us/sage_erp_x3/b/sageerp_x3_product_support_blog/posts/sage-x3-inter-site-transactions
it's just missing the intercompany setup to be complete.

Here is the last piece:

Welcome in the community!

Thanks Julien. Much appreciated! Glad to be part of the group.

Thanks Julien. Much appreciated! Glad to be part of the group.

I set everything up but when I try to save the PO I am getting this error. I have no idea what this means.

{
  "origin": "Convergence Server",
  "details": " - Error code : [500]",
  "diagnoses": [
    {
      "severity": "error",
      "sdataCode": "0",
      "stackTrace": "x3 Error; num:32, message:..\\..\\src\\exec2.c.2631 : Return not corresponding to Gosub line:0 type:1",
      "message": "Stack log"
    }
  ]
}