Can't transpose on PC and can't download 1 part on moble

Is there any way to do both without installing anything or going onto a sketchy website?
I have one piece I want to download (Death Odyssey - Arsi "Hakita" Patala) which is a woodwind duet. I want to change it from Bb, g to G,e and print the 1st part. Problem is, I can't do both. On mobile, I can transpose the music but can't download the 1st part. On PC, I can download the 1st part on its own but can't transpose it.

Unless I'm missing something, I can't find a way to do both and its getting annoying because it's not a uncommon occurrence. (Shoujo Shuumatsu Ryokou ED - More One Night) with me wanting to download the 1st part and lower it slightly (concert pitch to trumpet, janky with piano music). After 2 days I had to give up and stick with printing just the 1st part without transposing.

Is there a work around or do I need to install something?