Hi,
Here’s a link to the [https://download.lenovo.com/consumer/mobiles_pub/ideapad_yoga11s_hmm_en.pdf|service manual] for your laptop. Scroll to p.33 to view the necessary pre-requisite step and then the procedure to remove the keyboard.
Scroll to p.64-65 to find the part numbers for the various “national” keyboards (and the manufacturer of the keyboard) available for this model laptop.
If you search online, using the appropriate part number ''only'' in the search box of your browser, you’ll get results for suppliers of the part.
You can verify if the part number is correct as usually it is printed somewhere on the underside of the keyboard (obviously you’ll have to remove it to find out).
There is no mention in the manual regarding whether the keyboard has a backlight feature or not, so I don’t know about this.