Can't Use Tags or add tags to wordpress post i can only add categories but bot both at same time

[abhayvishnoi]

post = WordPressPost()
post.title = 'Post with new tags'
post.content = '...'
post.terms_names = {
'post_tag': ['tagA', 'another tag'],
'category': ['My Child Category'],
}
post.id = client.call(posts.NewPost(post))

i can't add or post tags using this code mentioned on the documentation i am only able to add categories if i use that code without post_tag