either play the 3 palm keys like a high f and add the key just in front of the right hand palm keys if you have it
or
the key above the first finger on the left hand the second finger on the left hand and the bottom of the three right hand palm keys.
To play F sharp on the alto saxophone, you typically use the following fingering: Press down the first, second, and third fingers of your left hand, and the first and second fingers of your right hand.
a flat is the same thing as g sharp. you play it with the one, two, and three finger keys down and the top spatula key, or the top key you play with your left pinky.
the lowest g is 1,2,3 on your top hand
The Front F key is the topmost left hand key and is pressed by the first finger. It was designed to provide an altissimo fingering for F6 as an alternate to using the palm keys.
An (A) Flat on an Alto Saxophone is the same as a (G) Sharp, so the three top keys down as if you were going to play a (G), PLUS the key on the left side of the sax, the key where typically you would place your pinkie. If you need more clarification, look on the internet for an Alto Sax fingering chart.
g sharp
you can play it by not pressing down any keys. OR for low c#, all six keys plus the second left pinky key (low C plus the pinky). this can be alternate fingering with an octave key
The lowest note on the alto saxophone is a Bb, and the fingering for this note is pressing down the first three keys on the left hand (index, middle, and ring fingers) and the first key on the right hand (index finger).
ghjkl
To play F sharp on the alto saxophone, press down the first finger of your left hand on the top key while keeping the rest of your fingers relaxed. This will produce the F sharp note.
A D flat is a C sharp... which is nothing
It's completely open.