Is this a printer that is already in your MacBook Printer list or a new printer to be Added?
If existing , try to reset the modem from within the System Admin screens and wait 30-60 seconds before restart. If MacBook doesn't show printer for selection, Restart the MacBook so it can refresh its IP address. Wi-Fi printing connections can take some time to establish. If still no go, can you try Adding it as a new printer. I have never found connecting wireless printers an instant experience - can wait 15-20 seconds for activity in the printer to commence - maybe due to age of PC and printers I have.