NoMethodError (undefined method `set_license_key' for CS:Module)

[iAaquibjawed]

1. I want to update the db of citie state by following the guide.

MaxMind update their databases weekly on Tuesdays.

Since Dec 30, 2019, MaxMind requires a license key (for free) to get download updates.

To get the license key:

Sign up for a MaxMind account: https://www.maxmind.com/en/geolite2/signup
Create a license key: https://www.maxmind.com/en/accounts/current/license-key
There's no need to download anything.

To update.
CS.set_license_key('MY_KEY')

CS.update

and while doing this getting error of undefined method.
2.6.5 :002 > CS.set_license_key Traceback (most recent call last): 2: from (irb):2 1: from (irb):2:in rescue in irb_binding'
NoMethodError (undefined method set_license_key' for CS:Module)