I have modified your mesh by adding edge loops and removed the wrinkles.
Here is the file https://blend-exchange.com/b/OZnLl2AZ
To remove your wrinkles and also curving the top of your mesh
You can start of by insetting the top face by selecting your face and pressing I on your keypad. So that you have something like this.
Now select the edge loop closest to the top face and press G twice on your keypad to edge slide and bring the edge loop down so that it makes the top curved and circular like you asked for.
Now inset the top face again
and then edge slide the loop again by pressing G twice on your keypad.
The last step is to tab into object mode select your apple stem and then Right-Click shade smooth Also I strongly recommend that you should make a few tweaks and adjustments to your mesh by just going around and selecting edge loops and rotating* and scaling them.