As soon as it launches you will be able to send the matching forms either electronically or via a paper option to each of your evaluators. You personally cannot submit LORs, they must come directly from your evaluators or through Interfolio.
Your committee will mail it out for you to AADSAS or, if they do an electronic copy, you will just have to authorize your pre-dent advisor in the Recommendations section of AADSAS and then they receive an email and upload it for you.