Listen to the original performance by Ensemble Vocal L'Alliance on streaming services like Spotify or YouTube Music to understand the intended dynamics and "spirit" of the piece.
The arrangement by Ensemble Vocal L’Alliance is a specific polyphonic version. You will need the sheet music to identify your specific voice part and the timing of the "Ensemble" entries. ensemble_vocal_lalliance_je_vous_salue_marie_di...
If you are organizing a virtual choir or practicing this specific arrangement, here is how you can approach it: Listen to the original performance by Ensemble Vocal