Don't open Office Folder. Just open word folder and use KMS Acivation cmd with admin right online. Done.
Don't use KMS key to enter in Office Product key column, this is for retail key only.
Open word, left hand side, choose Account, right hand side click Update options, click update now, it will update all office 2019 pro plus word, power point, access , outlook etc in one go to most update version. Enjoy.