Hi @honganhuynh1,
You will need to make sure to get the file content first, wherever it is coming from. All you need to do is add ".doc" to the end of your file name.
OneDrive Create file action
folder path - location where the file will be saved
file name - <name of file>.doc
file content - The raw html content
Note, this will create a .doc file. This will not work if you need to create a .docx file. That will require a premium connector as far as I can tell.