The Torah teaches us that Pharaoh brought korbanos (Shemos 14:10)
Pharaoh offered sacrifices
It is not clear what sacrifices Pharaoh brought, however the Torah tells us a revealing bit of information about who Pharaoh was (Shemos 32:25):
כי פרעה אהרון
Pharaoh was Aharon
It would therefore seem that he brought korbanos in the Mishkan, which was where Aharon brought his sacrifices.
However, Pharaoh made himself into a false god (Shemos Rabbah 9:8), and Heaven forfend that we would allow an idol into the Holy of Holies! How was this allowed?