Hello guys, this error is driving me mad each time i try to run the installation scrip in putty, what could be problem

[beautyinside20201]

https://aws.amazon.com/amazon-linux-2/
[root@ip-172-31-11-120 ~]# curl -0 http://vestacp.com/pub/vst-install.sh
#!/bin/bash
# Vesta installation wrapper
# http://vestacp.com

#
# Currently Supported Operating Systems:
#
# RHEL 5, 6, 7
# CentOS 5, 6, 7
# Debian 7, 8
# Ubuntu 12.04 - 18.04
#

# Am I root?
if [ "x$(id -u)" != 'x0' ]; then
echo 'Error: this script can only be executed by root'
exit 1
fi

# Check admin user account
if [ ! -z "$(grep ^admin: /etc/passwd)" ] && [ -z "$1" ]; then
echo "Error: user admin exists"
echo
echo 'Please remove admin user before proceeding.'
echo 'If you want to do it automatically run installer with -f option:'
echo "Example: bash $0 --force"
exit 1
fi

# Check admin group
if [ ! -z "$(grep ^admin: /etc/group)" ] && [ -z "$1" ]; then
echo "Error: group admin exists"
echo
echo 'Please remove admin group before proceeding.'
echo 'If you want to do it automatically run installer with -f option:'
echo "Example: bash $0 --force"
exit 1
fi

# Detect OS
case $(head -n1 /etc/issue | cut -f 1 -d ' ') in
Debian) type="debian" ;;
Ubuntu) type="ubuntu" ;;
Amazon) type="amazon" ;;
*) type="rhel" ;;
esac

# Check wget
if [ -e '/usr/bin/wget' ]; then
wget http://vestacp.com/pub/vst-install-$type.sh -O vst-install-$type.sh
if [ "$?" -eq '0' ]; then
bash vst-install-$type.sh $*
exit
else
echo "Error: vst-install-$type.sh download failed."
exit 1
fi
fi

# Check curl
if [ -e '/usr/bin/curl' ]; then
curl -O http://vestacp.com/pub/vst-install-$type.sh
if [ "$?" -eq '0' ]; then
bash vst-install-$type.sh $*
exit
else
echo "Error: vst-install-$type.sh download failed."
exit 1
fi
fi

exit
[root@ip-172-31-11-120 ~]#

[sandro]

Download installation script:

curl -O http://vestacp.com/pub/vst-install.sh

"-O" is not zero. OK?

For more: https://vestacp.com/install/