I don't know how to do it, but actually you can use a command which makes the password invisible.
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echo "Insert your Password: "
stty -echo
read MY_PASSWORD
echo ""
stty echo
echo "The password you entered is $MY_PASSWORD"
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the output of this script is:
Insert your Password:
The password you entered is lsdkjfsfh
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In case you knew all this, just forget it.
bye,
ducasio