When is the time for Fajr prayer before the Subh prayer, and when do we pray Subh alone, without the Fajr prayer, until the time for the supererogatory prayer arrives?

The time for the two Rak'ahs of Fajr begins with the true dawn and continues until the prayer is established. It is recommended to perform them early after the Adhan and to make them light. The obligatory prayer takes precedence over them if time is short or if the prayer is established before they are performed.