That is because it’s owned by root and should be considered as “sacred”, but as you seem to be a dev, this is how you copy files in there:
sudo cp --recursive ~/Documents/Source/MyApp/* /opt/lammp/
Where:
cpis similar toxcopy~means “my home directory”/Documents/Source/MyApp/the path to your project source/opt/lammp/The sacred directory…
And if you don’t know what recursion or * is, you’re faking that you’re a dev! 
As you also seem to be very new to Linux, please read this as well:
(All of it! It will save you tons of time afterwards and will prevent you from… erm… doing dumb things!)
