Allah (SWT) ordered us in many verses in Quran to obey the Prophet (SAWA).e.g. 3:32, :132, 4:59, 4:64, 4:80 and many other verses.
'The Prophet Muhammad (SAWA) clearly told the z Muslims to salute his progeny with him. He ordered Muslims to avoid the cut off salutation which does not salute his progeny with him. لا تُصَلّوا عليّ الصلاة البتراء.
Wassalam.