King Buffalo - Mammoth

I want to notate the solo in this song by King Buffalo but I am stumped why I cannot enter the chords. Hookpad seems very constrained.
The song goes, A#, G#, F, D#, C#, G#, D#, A#. I figure it is in the key of A# the soloing is in pentatonic minor. How can I get the first chord to be of a lower pitch as well since the notes are descending.
Also the is there a way to have A# rather than B flat as the notation?