An OMB number is a tracking number used by the Office of Management and Budget (OMB) for keeping track of form approvals and usage. It is not the actual form number.
OMB No. 1545-0715 is Form 1099-B. You don't fill out Form 1099-B. Your broker fills out Form 1099-B or a substitute, files it with the IRS, and sends you a copy. You certainly can enter into TurboTax a Form 1099-B that you receive from your broker. You enter it under investment sales.
I don't understand what you are saying about the form from your broker. Form 1099-B does not show profit or loss. It shows the proceeds of a sale and usually the basis, as well as a lot of other information. I assume that the statement about being "suitable for reporting only on Form OMB. 1545-0715" is something you see on the form from the broker. It sounds like some legal mumbo jumbo, possibly trying to say that the form they sent you is a valid substitute for an actual Form 1099-B. But if the form that the broker sent you shows only profit or loss, it is not a valid Form 1099-B.
