You must tell the AP where to find the file.
First, ensure the file is accessible. You can place it on a TFTP or FTP server reachable by the Access Point. Ap3g2-k9w7-tar.153-3.jf15.tar
: In several 15.3(3) versions, the HTTP/HTTPS server for the web GUI is disabled by default. Use the You must tell the AP where to find the file