My account is with Ameritrade as well, and in the past I have not been able to enter a bid online. However, I have not tried since the FINRA approval. I suspect we will have to call Ameritrade to put in a bid the first time, considering the current climate in the markets.
I am only expressing my personal opinions or repeating public information from SEC filings or media outlets-which may or may not be correct. Do your own investigating before investing!