apt install pure-ftpd
groupadd ftpgroup useradd ftpuser -g ftpgroup -s /sbin/nologin -d /dev/null ln -s /etc/pure-ftpd/conf/PureDB /etc/pure-ftpd/auth/60puredb pure-pw useradd hass -u ftpuser -g ftpgroup -d /media/photo/ -m pure-pw mkdb systemctl restart pure-ftpd.service
change listen port, for example 8021
echo ",8021" > /etc/pure-ftpd/conf/Bind
Use public IP of natted ftp server and open 29799-29899 port range in firewall
cd /etc/pure-ftpd/conf echo "yes" > DontResolve echo "185.91.188.100" > ForcePassiveIP echo "29799 29899" > PassivePortRange echo "0" > TLS
PureDB /etc/pureftpd.pdb MinUID 14 TLS 0
echo "/bin/false" >> /etc/shells
pure-pw useradd hass -u hass -g hass -d /home/hass/camera/ -m pure-pw mkdb