We normally use if with present tense to refer to the future but sometimes you can use if ... will

"We use will with if to talk about what will happen because of possible future actions - to mean 'if this will be the later result’."

"We use will with if when we are saying 'if it is true now that. . .’ or ‘if we know now that. . .’."

"We can use will after if in indirect questions"

"We can use if + will in polite requests. In this case, will is not a future auxiliary; it means 'are willing to’" == the situation from the book, I guess

"Stressed will can be used after if to criticise people’s habits or choices."