AX12 Update an Invoice line item quantity received - through X++

Hi

I am using code like this below - I think I shouldn't be creating a new axPurchLine, but trying to find it within the invoive and update it?

purchTable = PurchTable::find('00000006_064', true);
purchLine.initFromPurchTable(purchTable);
axPurchLine = AxPurchLine::newPurchLine(purchLine);
axpurchLine.parmItemId('1173'); /
axPurchLine.parmPurchQty(1);
axPurchLine.parmPurchPrice(65.65);
axPurchLine.doModify();