There are a number of verses in the Qur'an which encourage us to mention Allah and supplicate to Him.  Allah tells His Messenger :ﷺ  “And when My servants ask you concerning Me – indeed I am near.  I respond to the invocation of the supplicant when he calls upon Me.” (2:186)  Some supplications of prophets and righteous servants of Allah are cited in the Qur'an.  They teach us the etiquette of asking Him for relief and for blessings.