the Messenger of Allah (saas) said: "Indeed the supplication is the worship." Then he recited: "And your Lord said: Invoke Me, I will respond to you." (Using translation from Ibn Mājah 3828)
قَالَ رَسُولُ اللهِ ﷺ الدُّعَاءُ هُوَ الْعِبَادَةُ ثُمَّ قَرَأَ {ادْعُونِي أَسْتَجِبْ لَكُمْ} [غافر 60]