192.168.188.1 is a default IP address for wireless routers. It is used to log in to a router's admin dashboard to change or add to the default settings. Most wireless routers or ADSL modem routers are given this IP address by default. The majority of the time, when the router's official web address is down, a user must log into 192.168.188.1. 

Using this IP address to access the admin dashboard is identical to doing so via the official website. Simply enter the IP address rather than the usual website address in the address bar. Always check the IP address your router has been given; otherwise, you won't be able to log in.

For more - 

https://gingkoapp.com/192-168-188-1-wireless-extender-login-configuration  

https://techplanet.today/post/know-the-procedure-to-access-1921681881-login 

https://techplanet.today/post/how-anyone-can-successfully-log-in-to-1921681881