The Prophet (ﷺ) said: If you ever have to praise someone, say:
أَحْسِبُ فُلَانًا وَاللَّهُ حَسِيْبُهُ وَلَا أُزَكِّيْ عَلَى اللَّهِ أَحَدًا أَحْسِبُهُ كَذَا وَكَذَا
اَحْسِبُ فُلَانًا وَاللّٰهُ حَسِيْبُهٗ وَلَا اُزَكِّيْ عَلَى اللّٰهِ اَحَدًا اَحْسِبُهٗ كَذَا وَكَذَا
A’hsibu fulanan wallahu ‘hasiibuhu wa laa ‘uzakkii ‘alAllahi a’hadan a’hsibuhu kaza wa kaza
I think that he is so and so, and Allah knows exactly the truth, and I do not confirm anybody's good conduct before Allah, but I think him so and so.
It is a crime to slander a person from behind and praise him from the front. In the case of praise, one's special nature or quality can be praised. It is forbidden in the Hadith to praise someone or to say that someone is good. In the case of praise, I have to say: I think such a person is good; Confirmation cannot be expressed.