How can I use Termux with the JuiceSSH interface?
It's already supported.
I created a ~/.termux/termux.properties with the following contents:
extra-keys = [ \
 ['ESC','|','/','-','HOME','UP','END','PGUP'], \
 ['TAB','CTRL','ALT','DEL','LEFT','DOWN','RIGHT','PGDN'] \
]
extra-keys-style = arrows-only

It's enabled by opening the left sidebar (swipe from the left screen edge) and long-pressing on the &quot;keyboard&quot; button.
Documentation here: https://wiki.termux.com/wiki/Touch_Keyboard