在发送Firebase电子邮件之前，您可以设置模板的语言.您可以在Firebase控制台中以其他语言编辑模板(英语模板可以编辑唯一主题)

Before sending firebase email you can set the language of a template. You can edit templates in different languages in firebase console (Template in English you can edit the only subject)

firebase.auth().languageCode = 'ua';

firebase.auth().currentUser.sendEmailVerification()