@bethlehem besides all those great answer already given, here are my 2 cents. Get the service manual for the Flex 6-14 [https://download.lenovo.com/consumer/mobiles_pub/flex6_14ikb_flex6_14arr_hmm_20200316.pdf|from here] That will help you to work on it.
The issue here is that Lenovo, as well as all the other makers, have opted to solidly connect the keyboard to the upper case (usually via rivets, either metal or plastic), with the idea that you need to replace the whole top cover/palmrest for this. If you find just a replacement keyboard, you could try and remove those rivets and replace the keyboard only. You will then need to secure the keyboard with a boat-load of small screws. Otherwise you have to replace the complete top case. No easy task but possible