In every thing by prayer and supplication … let your requests be made known unto God. — Phil 4:6 The synonym for prayer, translated here “supplication” and elsewhere “petition,” is strange for its redundancy.
In Greek it is δέησις (deēsis), which means a need so urgent you turn to begging. You have no other hope. It evokes the utter powerlessness of being prostrated before a potentate who holds your life in his hands. Pleading, nothing more.
So many times, my prayers cover things I can also cover. These are things I need to get done, I can done. I just want God to help me do them efficiently.
Then there are needs about which I am exasperatingly powerless. About those needs, I tend to get frustrated, get mad, sulk. In fact, if I’m brutally honest about myself, I complain more than I pray.
That seems to me to be what Paul is addressing. Yes, pray, but also plead (supplicate, make petition) to a God who alone can help you. You can trust God for the needs that are completely out of your control.