This is obviously a question about termux and terminfo rather than Emacs, so I will be brief.
The terminfo database is normally stored in
/usr/share/terminfo. For example, the entry for
screen.xterm-256color would be in the file called
You can use the
infocmp program to show what is in these files. Check the man page for details, but if you give it a terminal name it will print out everything it knows about it. It sounds like in your current setup
infocmp xterm-256color will succeed while
infocmp screen.xterm-256color will give you an error. See the man page for more details, obviously.
tic compiles a terminfo file from it’s source code, if you happen to find it and don’t have a better way to install it. Again, read the man page if you have any questions.
I don’t know anything specific about Termux, so I cannot tell you how to install things with it; you will have to consult it’s own documentation. Know however that
screen.xterm-256color is a very normal terminal name to use; it should be in your terminfo database if it is installed correctly. Usually you install the entire database from a single OS package and you don’t have to mess about with individual entries unless you have installed a brand new terminal emulator.