Recommendation letter from employer

I received a letter of recommendation from my employer from the intership i did over the summer. The problem is, how would I send this to colleges. For example, is there a way to put it on common app? For nyu on common app, it said I can send in additional recommendation letters but it told me to put in the email of the employer as well. Would nyu email the employer so my employer can email them the letter directly or do I send the letter to nyu or how does it work?

You can photocopy it and snail mail it to your target colleges that accept supplemental rec letters (check 1st: many do not want them). Mailing’s perfectly acceptable.