Yes, you can. If you log in and look on the LOR page it should still let you add one. I had to do this last year after I had submitted. If you are unsure look in the FAQ's section of pharmcas. HTH.
thank you. Also I was wondering, when I past my personal statement into their submission box, does paragraph indention matter? Because when I view the printable version of my application the indention do not show up.