YAMon v4 - install/config problems

Hi, just tried Yamon to monitor my network bandwidth and came across some problems, if you could help @al_c
first of all thank you for the efforts in making this software.

Device: Bthub_v5a
Openwrt: 19.07.3 r11063-85e04e9f46

Using below guide to install and configure

http://usage-monitoring.com/v4Install+Validate.php

after installation the symlinks were not working and could not access
http://192.168.1.1/yamon/
install.sh created the symlink pointing to "/tmp/yamon"
therefore had to make a new symlink to access reports
ln -s /tmp/www /www/yamon

after install
logs show error:

/opt/YAMon4/update-live-data.sh: line 99: can't create /tmp/www/js/live_data4.js: nonexistent directory iptables: No chain/target/match by that name. cat: can't open '/tmp/yamon/mac-ip.txt': No such file or directory /opt/YAMon4/update-live-data.sh: line 65: can't create /tmp/www/js/live_data4.js: nonexistent directory

/opt/YAMon4/update-reports.sh: line 130: arithmetic syntax error

and Active connections show no connection.

help!!!