Ubuntu :: Read Not Allowing Operators In Shell Scripts

I'm trying to write a small application controlling spotify, running under wine, that I can run from my desktop computer and use via SSH on my mobile phone, and so far I've been quite successful. At least until just recently, when I tried to use the read command to read a single key-press on my phone, and use that input instead of having to type the number for item in the menu I've created. I tried to simply use the read command to silently listen to one key-press and output it to the variable opt. To do this I tried:

read -s -n1 opt

When I ran this in a shell-script this I got:

read: 1: Illegal option -s

Seeing this, I tried to remove the -s operator, which left me with:

read: 1: Illegal option -n

I decided to remove all operators and echo the variable opt, leaving me with:

read opt
echo "$opt"

Which worked as expected. It echoed the key that I had pressed. I moved over to my terminal window and tried the read command from there, and it did exactly what it should. It silently recorded one key-press to the variable opt.

why isn't read working with operators in shell scripts?