sternly

adverb
1
in a serious way that often shows that you do not approve of somebody/something; in a way that shows you expect somebody to obey you
به طور جدی, قاطعانه, با سخت‌گیری, تحکم‌آمیزانه
2
in a serious and difficult way
با جدیت, به طور سختگیرانه, به طور جدی
They were sternly tested by the opposing team.