To add this was Iran's statement a few hours after the strike

❗️Statement from the Secretariat of Iran’s Supreme National Security Council regarding Iran’s missile response to the US aggression:

"So whoever has assaulted you, then assault him in the same way that he has assaulted you." — [Qur’an 2:194]

In response to the aggressive and brazen US attack on Iran’s nuclear sites and facilities, the powerful armed forces of the Islamic Republic of Iran struck the American airbase in Al-Udeid, Qatar, a few hours ago.

The number of missiles used in this successful operation matched the number of bombs the United States employed in its attack on Iran’s nuclear facilities. The base targeted by Iran’s capable forces was located at a significant distance from urban areas and residential zones in Qatar.

This operation posed no threat whatsoever to our friendly and brotherly country, Qatar, or its honorable people. The Islamic Republic of Iran remains committed to preserving and continuing the warm and historic relations with Qatar."

The cradle

So same as how they informed Iraq in the past before launching strikes.

According to NY Times:

Three Iranian officials said that Iran had given advance notice that attacks were coming, as a way to minimize casualties. The officials said Iran needed to be seen striking back at the United States, but in a way that allowed all sides an exit ramp. They described it as a similar strategy to one used in 2020, when Iran gave a heads-up before firing ballistic missiles at an American base in Iraq after the assassination of its top general.