I am passing arguments to the shell script below ./script.sh pan.tgz 192.168.3.1 ABCXYZ
#!/bin/sh
echo $1 $2 $3
file=$1
host=$2
key=$3
curl -kv -o ${file} 'https://${host}/api/?type=export&category=device-state&key=${key}'
but getting error curl: (6) Could not resolve host: $host