The reason for this issue is that we do not have the same end points as sales order api.
- postLine
- putLine
- deleteLine
It will be interesting maybe to know why we do not have this currently in Dolibarr for Supplier Orders.
The code to update an order on Supplier Order it just simple fields. However, the lines field is an array that can contain one or more llx_commande_fournisseurdet entities.
