Message ID set by Btwentyfour Open Commerce Platform.

ordrsp_Examples
 <orderResponse text="Btwentyfour Example OrderResponse" environment="Production" status="ORDER_STATUS_REGISTERED" orderType="REGULAR_ORDER"  currency="SEK" messageId="237356" messageDate="2020-08-26T12:19:05.167Z"> 
ordrsp_XPATH

/b24Message/orderResponse/@messageId

ordrsp_Type
Number
ordrsp_Sort
1600