Open the plain text editor and copy eveything starting with <a class= through </script> then past the code in the plain text editor on your page.
NOTE: twitter feeds may not display in firefox if using hardware acceleration option or certain add-ons
A post must be public to be embeddable. You can't embed anything set to be seen only by friends. You can view the instructions @ https://developers.facebook.com/blog/post/2013/07/31/introducing-embedded-posts/
Below is a sample of how an embedded post displays on your page.
