It is unclear on what basis Mustafa is making these statements. The Qur’an says:

The month of Ramadan in which was revealed the Qur’an, a guidance for the people and clear proofs of guidance and criterion. So whoever sights the month, let him fast it; and whoever is ill or on a journey – then an equal number of other days. Allah intends for you ease and does not intend for you hardship and for you to complete the period and to glorify Allah for that which He has guided you; and perhaps you will be grateful….It has been made permissible for you the night preceding fasting to go to your wives. They are clothing for you and you are clothing for them. Allah knows that you used to deceive yourselves, so He accepted your repentance and forgave you. So now, have relations with them and seek that which Allah has decreed for you. And eat and drink until the white thread of dawn becomes distinct to you from the black thread. Then complete the fast until the sunset. And do not have relations with them as long as you are staying for worship in the mosques. These are the limits of Allah, so do not approach them. Thus does Allah make clear His ordinances to the people that they may become righteous.” (Qur’an 2:185, 187)

In any case, since Paigham Mustafa doesn’t accept or has some interpretation of it that differs from the prevailing one, Muslims have threatened to kill him. “Shut up or else you will get your head chopped off … shut up or else you will be beheaded … shut up you Kafir dog … you will get beheaded … we will kill you kafir. A separate message sent privately by another critic said: “Quran says kill people like you. You deserve to be killed. We will kill you. Another post by a third critic warned: “Don’t talk about Islam you Kafir. Remove this post Kafir. Or else you will get killed like Rashad Khalifa.”

A Muslim murdered Rashad Khalifa in Arizona in 1990 for deviating from Islamic orthodoxy.

“‘You will get your head chopped off’ – Scots Muslim writer threatened by extremists,” by Peter Swindon, Sunday Herald, June 3, 2018 (thanks to The Religion of Peace):