Saying "please" in a dua (supplication) is not considered haram (forbidden) in Islam.
Dua is a form of communication with Allah (SWT), and expressing humility and respect is encouraged. While using the word "please" is not explicitly mentioned in Islamic texts, it is generally understood that expressing a sense of need and dependence on Allah (SWT) is a key aspect of dua.
Therefore, incorporating words like "please" or similar expressions of humility can be seen as a way of emphasizing the supplicant's need and reliance on Allah (SWT). Ultimately, the intention behind the dua is what matters most.
Example:
Instead of saying "Oh Allah, grant me this," one might say "Oh Allah, please grant me this."
Practical Insight:
It is important to remember that dua is a personal act of worship. While there are general guidelines and practices, ultimately, the way one chooses to express their supplication is up to them, as long as it remains within the boundaries of Islamic teachings.