Q621: A muqtadi not doing 2 sajdah with imam

Assalamu alaykum.
Maulana,can you please help me with a kwik mas’ala,if u muqtadi following an imam does not do both sajdahs whilst in salaah,is his salaah accepted as the imam did do both sajdahs,jazakallah

Walaikumussalam w w
Did he do them after imam had raised his head or did he not do them at all? If he did them, his salah will be valid even though there was delay in following, if this was for genuine reason like old age, slow movement, forgivable, if no reason then makrooh, if no sajdah then salah is faasid and has to be repeated, bcos 2 fardh omitted, wassalam