Online Gaming - Applying script

hello everyone,

I really appreciate if someone can help me to apply the below link on my router,

my issue mainly with Call of duty MW Rebirth or warzone is (100% divided as 80% Packet burst and 20% high latency)

can you highlight for me which part I have to enter and how ? from where in the web UI ?
or is it cmd ? really appreciate your help, maybe it could resolve my issues,

also I wanted to mentioned to you guys my setup as it may show you if I did something wrong,

I'm new to openwrt (one month of usage) and I'm still not expert with it...

my setup as the following:

Main 4G modem CAT19(DMZ on for TP link router- Static IP)>>
Tp-Link Archer C7 V2.0 (connected to Wan port - DHCP on - SQM on)>>
Wlan2.4 & 5 on(SQM on but disabled after restart " it seems common issue as I read here, but is ok !">>
PS5 on LAN port No.1 on VLAN 10 (Static IP to have Open NAT type as per the following link ( Thank you!).

I have no issue with the whole networks (as it seems to me so far) but still wanted to make my connection better for online gaming

also if you have any suggestion, please let me know

Thank you in advance...