College letters of REC question

Hey guys! Im graduating in 2018 and I made a Common App account on August. I asked two of my teachers before the 2017 school year ended if they could do my letter and they said yes.

On August 1st, I logged into my Common App and I assigned my teachers to the college I am applying to and invited them. Im not sure if I was supposed to do that.

Did I invite them too early or too late?

You’re fine.