If used in a sentence with an event that may happen in the future, and even if you are talking about an event is present as future simple tense is used instead of the future tense.
If used in conditional sentences To events that may occur in the future. Despite talking about a future event or just use the present simple tense future tense.
Use if in conditional sentences to an event that may occur in the future. Even talking about events that the future way is to use a present simple tense instead future tense.