beas service layer and b1up universal function (ExecuteBeasScript)

Hi,

I'm trying to create a material posting to a production order using a B1Up Universal Function (macro "ExecuteBeasScript"). I'm using the following beas-servicelayer script for this. Unfortunately, it doesn't work (the script itself has been successfully tested), and I can't find any examples for the combination of b1up macro and beas-servicelayer. Is this even possible? And if so, what are the prerequisites and what is the syntax in the B1Up macro (e.g., regarding line breaks... the <cr_lf> tag doesn't work...)

Thank you very much for any advice... I´m not an expert in this, but I have to get a customers requirement solved....

Toby

Here is my example of the B1Up universal function (macro):

ExecuteBeasScript(
#define ls_json
{"Transaction":"issuewo",
"DocumentLines":[
  {
    "Base_DocEntry":1063,
    "Base_LineNumber":10,
    "ItemCode":"1000297",
    "Quantity":1,
    "WhsCode":"010"
  }
]
}
 
#end
instance bsl b
b.post=IssueWo=<ls_json>
messagebox=<b.ret_code> <b.ret_text> <b.ret_value>);