You can put a product code and Description field in inventory items or non-inventory items, but there is no way to put in a product code for something that you want to buy once and once only. Sometimes you don’t plan on buying more, but you end up doing so. It’s very useful to have the product code to find the item again on a website three years later!
Would it be possible to use the product field to either select inventory item, non inventory item or “new item” and type in product code when selecting new item?
Are you referring to the Item field? If so, that field has the specific purpose of calling up data for defined items. Since your one-off purchase isn’t defined, by definition, there would be nothing to call up. So Manager tells you no match has been found. And the Item code is meant to be your item code, not some supplier’s.
Yes the Item field is meant for calling up an inventory item or non-inventory item and is very useful for that. And as you state currently displays nothing if you type an entry that doesn’t exist as it is effectively a search bar.
But my point is there is no way to add a product code for any product that you buy from a supplier unless you put it in inventory items or non-inventory items.
I can’t think of how many times I have bought something whether for personal or for business, not planning on buying it again, and then later on deciding actually I would not mind another one - having the part code of the supplier is essential if you want to find the product on the website again as very often they look similar like DVD drives or CPU’s, but can be very different in specs or Dutch Liqourice.