Guide me on Implementing Derived Price.

@Tushar Konde That message means the line editor couldn't find a usable derived price record for the product you just added. A derived product doesn't price from a normal price book entry. It prices from a derived price that points at a contributing product.

The usual miss is adding the derived product on its own. The contributing product has to already be on the quote, and the derived price record has to use that product as its source, on the same price book and selling model as the quote. If any of those don't match, the lookup comes back empty and you get Derived Price Record with nothing after it.

Check the derived price record first, then add the source product, then the derived one. If the record is right and the source is already on the quote, the pricing procedure on that quote isn't running the derived price element, so the line still has nothing to price with.