Firstly congratulations for getting this far! Well this is the final missing note and the highest note there is, a semi-tone above the 10 blow and a third above the 10 draw, in second position it would be the bluesy flat 5. You probably won’t come way up here too much in everyday playing but it’s here all the same.
How to do it
If you can get the 9 overblow, you should be able to get this, it’s quite similar but just a bit higher. You may find it easier by going into it from the 10 blow bend.