Your hand position must be incorrect.

The easiest way is to research it on line.

You need to have your hand in a more horizontal  to the floor position and then practice in front of a mirror.

Or try a different horn. Go to a music shop and try one out.

I have never heard of your particular horn so it may simply be made badly.

Good Luck

Hi,
I have small hands for a male musician and I have similar problems with the b-flat key.  Every saxophone I have tried has different challenges.  I’ve figured it out on my Selmer Mark 7.  On this horn it has taken me quite some time to learn how to hit the b-flat portion of the key cluster, without ’rubbing up’ against any other keys.....and an inadvertent touch will open something up you don’t want, thus making the b-flat hard to get out.  In addition, my horn needed some adjusting to make sure all of the mechanics on the bell were operating perfectly.

Interestingly, my old Conn is the easiest to find the b-flat key on, but having small hands on that instrument causes all sorts of other ergonomic problems.

Only other solution i have heard proposed is getting a key riser for that b-flat key so that little finger on your left hand doesn’t have to reach quite as far.  It is amazing what an 1/8” or 1/4” will do.....though I have not needed to resort to this option.
 

I too have problems with the modern Bb position because my left pinky finger was dislocated and will not extend full length.  I play vintage horms where Bb is in line horizontally with the C# and B keys.  However, I have also seen some techs bend the left hand G touchpiece down a bit toward the pinky table to reduce the distance slightly.  You might want to run this past a tech and see if it might be a workable solution for you.