Future Continuous has two different forms: “will be doing ” and “be going to be doing”.
The form of this tense:
Subject + Will be + Infinitive + Ing
Sujet + To be + going to be + Infinitif + Ing
I will be reading the book (in the future)
Tonight, we will be eating dinner
We use it to speak about a longer action in the future, in this example Tonight, we will be eating dinner,the action of eating is longer and take time!