Following are steps for faxing on Canon MX490:
*Make sure that the machine is turned on.
*Press the FAX button.
*The Fax standby screen is displayed.
*Load documents on the platen glass or in the ADF.
*When sending a double-sided document, load the document on the platen glass. Double-sided documents cannot be automatically scanned and sent from the ADF.
*Adjust the scan contrast and resolution as necessary.
Setting Items for Sending Faxes
*Use the Numeric buttons to dial the recipient's fax/telephone number.
*Use the buttons to dial the recipient's fax/telephone number.
*By pressing this button once, "#" is entered. By pressing this button one more time, "P" is entered.
*Press the Color button for color transmission, or the Black button for black & white transmission.
*The machine starts scanning the document.
*Do not open the document cover until scanning is completed.
For complete pictorial and detailed steps please check Canon PIXMA MX490 Manual- https://guideusermanual.com/product-name-pixma-mx490-manual&po=158078&lang=English