The Future Perfect is not a tense but a structure made of combining other structures together. It is often described as a combination of the modal verb Will and the Present Perfect but becuase Will is a modal verb it must always be followed by an infinitive. Have does not change as it would do in the present perfect.
The negative is formed on Will not Have
Subject + Will + Have + Participle + Object
Subject + Will not/Won't + Have + Participle + Object
Will + Subject + Have + Participle + Object?
It is possible to use Shall instead of Will when in more formal situations. For more information on Shall/We click here
It is worth remembering that we can contract Will to 'll and it is very common in speaking for native speakers to also contract Have so you may hear 'll've but do not use it in your writing!
The Future Perfect is used to talk about actions or activities that will be completed between now and a moment in the future.
By ten o'clock tonight, I will have finished my essay
Your plane will have landed before we eat breakfast tomorrow
English grammar often revolves around a point of narrative. For the Future Perfect there are two points to consider, the moment of speaking in the present and a moment in the future being referenced. The Future Perfect action happens between those two points.
Specifying that second point of time is vital to using the Future Perfect, if you do not make a reference to a specific moment in the future or one has not been established in context then the "Future Simple" Will + Infinitive is more appropriate
The Fundamental future forms in Englsh
Will, be going to & the present continuous
Future actions & intentions
Predictions about the future
Expressions to talk about the future:
Be due to
Be about to/Be on the point of
To emphasise the duration of an action or activity ongoing at a specific moment in the future
Duration of a future activity
Looking into the past from the future