PLz help in fixing bathtub faucet Handle that fell off

[Newbie123]

Would you plz let me know how to fix this? I am completely newbie and don't wanna break any thread..
Thanks a ton!

 

[hj]

cannot tell from the picture, but the "button" on top of the handle may come off with a screw underneath it.

 

[Sponsor]

 

[Newbie123]

cannot tell from the picture, but the "button" on top of the handle may come off with a screw underneath it.

Thank you very much . There is a screw under that button: Any idea? Thank you so much.