In the formula of Ampere force F = bil, why is it that B and I are not necessarily vertical, while f must be perpendicular to B and I

In the formula of Ampere force F = bil, why is it that B and I are not necessarily vertical, while f must be perpendicular to B and I

This is determined by the left-handed rule, and F is perpendicular to the plane determined by B and I. in essence, it is the cross product of the current vector and the magnetic induction vector f = I × B