Is this the correct way to loss harvest?

I’m using robinhood in my main account. I believe robinhood uses FIFO to calculate gains. So let’s say a stock goes from $9 to $4, and I hold 200 shares, then can I buy 200 shares at $4 and then sell 200 shares at 4$. That way I realized a $1000 dollar loss, while my position remains the same.

Am I doing this correctly?