What is the technique to get them to work?

Assuming your flute is in proper working order, no special technique should be necessary. Low notes especially can be affected by leaks in the pads/headjoint cork/joints/etc. Take your flute to a tech and see if they find anything wrong with it. If they do, having those problems fixed should take care of you. If they don't, try experimenting with your air (likely angling your air downward more, and slowing the airstream slightly will help).

Well I just got it today so I'm not very good yet so it's probably just my breath. Thank You!

That could be. If, with more practice, you still notice problems with low notes, then taking it to a tech would be a good idea. Most people do have problems with the low notes moreso than the rest of the flute's range, so you're not unusual in that aspect. Best of luck to you!

On the lower notes, push out more air or the notes will be incredibly flat. Also, try playing the lower notes from G chromatically down to C, or B if you can. Take it very slowly and play the notes as loud as possible. Once u learn to play the notes loudly, you can learn to control them.

Pushing more air will not necessarily help...In fact, it may make matters worse. It's less about how much air you're using than how you're using it. And blowing more air is not the way to correct notes that are horrifically flat. That should be adjusted using the angle at which the airstream contacts the edge of the embouchure hole (in this case you would want to blow slightly higher to raise the pitch). Before learning to play the notes as loudly as possible, you need to learn to produce these notes reliably, and control their pitch and tone. Then you can work on adding the next layer of complexity, which would include playing at varying dynamic levels without throwing off pitch or tone, or jumping an octave. Learning to control the notes is much more important in the beginning than learning to play them loudly.

Thank You everyone!

piccolo, sometimes you have to play softly to develop a good tone, please don't advise anyone to force low notes out of the flute, it rarely works and is amateurish advice at best.

One learning method for beginners(the one I went through) is practising from A up (say up to C, can´t remember but could check in the book) and then go lower G, F. It was a full year before I attempted the low C and 6 months for the low D.

If you received your flute so recently, it is normal you have some difficulties. Try to follow Trevor Wye's book for beginners, (book I, blue cover) if you have not chosen another.

And enjoy it!

maybe you could try dropping your jaw a little.

Practice...longtones. Practice them soft as well as loud, if you can play in tune softly and evenly up to high G then you have all the skills to play the low notes. Hum the notes as you play them and the limited air available will force you to learn how to 'focus' the air on the sweet spot.

You should just blow lighter than you do with the really High note. It only took me about fifteen minutes to learn them. I am way younger that our best flute player in our school district and I could play them before she could. It just takes time. You will eventually figure it out.

Blowing harder or more gently is not how you determine which octave you're playing in. That is determined primarily by the angle of the airstream, as well as fingerings (depending on exactly what note is in question).

flutesrbest, Chris is, yet again, correct...the size of the embochure and the angle of the air determine the proper production of high and low notes, the air may appear to be going slower for low notes but only because the air is travelling through a larger apeture, or opening...

my airstream is consistently strong in all ranges...

Of course Chris is alway right! Chris is going to make a great teach if he isn't one already.