I am almost positive you have to wait for OTCAS to open. When you create your OTCAS profile, there is a LOR section. You have to send a link from that page to whoever it is that is writing one for you. It is a specific OTCAS link to which the reference will upload their LOR themself. You will not see what they write unless you ask them to send it to you directly as well.Thanks! If I ask a professor/OT for a LOR now when the next OTCAS cycle hasn't opened yet, where would the letter go/be submitted in the meantime? Or would they have to hold off on it until the next cycle opens? When is a good time to ask for LORs?
However, it is not a bad idea to give them a huge heads up! Ask if they will write you a LOR well in advance. I would allow a couple months so they aren’t pressured. If they say yes, just let them know you’ll need it submitted in mid July, at which point you will be sending them the link to submit it. Hope this helps!