Using your phone/laptop, connect to the TP-Link router's wifi. The default wifi name can be found at the back of the router under 'SSID' (it should look something like 'TP-Link_XXXX')
After connecting, from your browser go to tplinkwifi.net. Go to 'Quick Setup'. Select 'Range Extender' and press Next
The router will scan for available wifi networks. Select your wifi under the 'Connect' column and press Next
Depending on your router, it might also scan for available 5G networks. Press Next to skip this option
Enter your current wifi password. At the bottom of the page, select 'Customize' and type in 'QashierPOS' under the <Extended 2.4GHz SSID> field
Press 'Next' without changing anything on this page
Press 'Finish' to confirm
Your router will now restart. After 2 mins, you can now connect your POS terminal and wifi printer(s) to 'QashierPOS' (note that the wifi password will be the same as your current wifi password)