If it is easy to say rapport /ræ’pɔːr/ without the ‘t’ sounding, then you can pronounce words like depot /ˈdep.əʊ/ and debut /ˈdeɪ.bju/. Pronounce depot just like ghetto, and debut like fable – except that the second syllable in debut sounds like the way you pronounce ‘you‘. Never pronounce the letter ‘t’.

Rapport is a close and harmonious relationship in which the people or groups concerned understand each other’s feelings or ideas and communicate well. For example, she was able to establish a good rapport with the children.

It is important to note that many words in English that are derived from French (like depot /ˈdep.əʊ/, sachet /ˈsæʃ.eɪ/, rapport /ræpˈɔːr/, debut /ˈdeɪ.bju/, chalet /ˈʃæl.eɪ/, ballet /ˈbæl.eɪ/, sachet /ˈsæʃ.eɪ/, bouquet /buˈkeɪ/, depot /ˈdep.əʊ/, mortgage /ˈmɔː.ɡɪdʒ/, etc.) have the silent letter t.

There’s a simple logic behind this. In French, the last consonants in many words are not pronounced.

https://newsroundtheclock.com/nrtc-english-the-letter-t-isnt-pronounced-in-debut-sachet-depot-chalet-rapport-and-mortgage/