@rahman75922 the keyboard is part of the upper case. It is not a separately replaceable item. Now, that is not to say it can't be done but you will have to try to remove all of the plastic rivets and then find some other way for attaching the new keyboard. Small screws and some adhesive "may" work. This will require you to find a separate keyboard that is meant for your Yoga.
Download the Hardware Maintenance Manual [https://download.lenovo.com/consumer/mobiles_pub/yoga730-15iwl_hmm_201809.pdf|from here] It will show you how to remove the upper case and also have the Lenovo part number for a replacement.