He responds to invocations

Fourteen times in the Qur'an you are going to find and they ask you and if they ask you, Yasaloonaka (يسألونَكَ) and Wa Ithaa Sa'alaka (وإذَا سألك) in
Yas'aloonaka and one Wa Ithaa Sa'alaka). Every one of the times when Allah says and they ask you, you are going to find Qul (قل) (and tell them), except one time in the Qur'an which is about Du'aa. It is consistent in every one of them, except in Du'aa. If they ask you, and there is no Qul (and tell them). It is trying to convey pure Tawheed to you, that this is a relationship between you and Allah directly.
No Messenger, no Wali and not even the Prophet sallallahu 'alayhi wa sallam is between you and Allah. The Du'aa is directly between you and Allah. It is complete Tawheed, pure Tawheed, and that is why there is no Qul in it.
[Gems of Ramadan]

Be consistent in your dua’s and ask for the impossible, nothing is impossible for Allah, He just says Be, and it is.
Make the most of this blessed days.

@FadingShadow