$_env is unset due to how you pass arguments to getopts.

You need

while getopts "p:e:" op
                  ^
              mandatory here

Check:

help getopts | less

$_env is unset due to how you pass arguments to getopts.

You need to add a colon after the e to tell getopts the option takes an argument.

while getopts "p:e:" op
                  ^
              mandatory here

Check:

help getopts | less