Moses was taught in all the language and writing of the Egyptians.
Aaron lived in Egypt his whole life up to the point of the Exodus.
Those men went in to Pharaoh and spoke to him about Jehovah the God of the Hebrews.
They used Jehovah's name in Egyptian.
God's name translated into Egyptian hieroglyphics can be found at the Temple of Soleb in Sudan dating from prior to 1300 BC. It's a translation and not just a transliteration of the Tetragrammaton. If it was a transliteration, there would be two of the same glyphs. But instead, there are four different glyphs: π π π ±π―
https://www.quora.com/Since-Moses-and-Aaron-spoke-Gods-name-Jehovah-to-Pharaoh-in-Egyptian-and-since-the-Temple-of-Soleb-has-Gods-name-Jehovah-in-Egyptian-why-do-some-people-today-freak-out-about-saying-Gods-name-Jehovah-in-other/answer/EasyAddendum?prompt_topic_bio=1
https://youtu.be/pGEOZ5YI22M?si=f5Doayi99Ni_qocy
(Incidentally, @Duran, there is no "v" in Egyptian hieroglyphics, but that didn't stop Jehovah from making His name known to Pharaoh. In Egyptian. Before Pharaoh died for being an unrepentant stiff-necked opposer of "He Who Causes To Become.")
"How do you feel about the use of the name Jehovah now?"
"Call on Jehovah, while He is near!"
"The day of Jehovah is near, and He is making an accounting!"
"Repent, and call on the name of Jehovah, that seasons of refreshing may come and peaceπthrough Christ Jesus, the Son of Jehovah God and the appointed savior of all those putting faith in him."