Should an upasaka or sadhaka not perform feet namaskaram to other people?

I have not taken deeksha before and I don't have a Guru.

I just have a doubt to ask.

I have heard that upasakas/sadhakas are not allowed to perform feet namaskaram to other people.

Should an upasaka or sadhaka not perform feet namaskaram (Sashtanga Namaskaram/Panchanga Namaskaram) to other people (except to his Guru and Devata)?

Is there such a rule?