Is it permissible to pray Duha in congregation, and if so, should the recitation be audible or silent?

Congregational prayer is not recommended for supererogatory (nafl) prayers, except for those that the Prophet, peace and blessings be upon him, regularly performed in congregation, such as the Eclipse Prayer (Salat al-Kusuf), the Prayer for Rain (Salat al-Istisqa), and the Tarawih prayer. As for other supererogatory prayers, like the Duha prayer (forenoon prayer) and the night vigil prayer (Qiyam (definition) al-Layl, other than Tarawih), congregational prayer is not recommended for them. However, it is permissible occasionally, without making it a regular practice. The fundamental principle for daytime prayers is that they are to be recited silently. Therefore, whoever performs the Duha prayer with a congregation should recite silently.