According to the kafir Ibn Hajar al Asqalani, believing in Al-Rububiyya is enough to be a Muslim, but if someone believes that Allah is in heaven, then he is still a kafir because they consider it anthropomorphism.
Ibn Hajar said: When the kafir acknowledges the unity of Al-Rahman, he is considered a Muslim.
If someone attributed to tajseem (anthropomorphism) from among the Jews says: Nobody has the right to be worshiped except the One in heaven, then he is not a believer, unless it is a layman who does not understand what tajseem is, then this is enough. (Fath Al-Bari 13/359)