I wanted to clear a confusion regarding people saying that it is not permissible to do sujud on the upper face of Khak e Shifa on which the name of the Imam AS is written as it will be shirk. They say that we can only do Sujud before Allah so we should turn it upside down while doing Sujud. I don’t have any clear proof that I can tell them about it being wrong or right. Please guide me through any reference.

No that’s not haram, because even though the name of the Imam is mentioned, we are not worshipping the Imam. The name of the Imam is just a blessing on the torbah. That’s like prostrating on a piece of paper that has someone’s name on it—that’s not haram.