This function is equivalent to the GetTradingPartnerLocationVariable
GetTradingPartnerVariable('VariablenName', ['GLN'])
GetTradingPartnerVariable('TestMode')
GetTradingPartnerVariable('TestMode', '4035811000006')
Note: If the variable is created as a flag and you want to query for the boolean value in the mapping or job, the function must be encapsulated again with IsTrue() or IsFalse().
IsTrue(GetTradingPartnerVariable('TestMode'))