Login error message is not translated

hello.

My website is set as Vietnamese, but I’m having a problem with the login failure message being in English.

• Wrong password error: Error: The password you entered for the username <> is incorrect
• Wrong username error: Error: The username <> is not registered on this site. If you are unsure of your username, try your email address instead.

I checked the vi.po file in the /wp-content/languages/ folder, but that text is not in the po file.

How can I make this error message appear in Vietnamese?

Thanks.