The image is too bright?

There are probably many different ways to do this.  A simple way would be to select the person, add a levels adjustment layer, and make some levels adjustment.  Here, I just used the Output level of the white point to tone down the brightness.  Feathering the selection would also help blend the two images.

You can also start off with the Automerge Compose Guided Edit.  This has a tool to Auto Match Color Tone.  In this case, the tool actually brightened the person, but using the Luminosity slider I  lowered the brightness.

Hope this helps.