nickname

I call them that.

私は呼びます

I call my friend by their nickname.

私は友達をあだ名で呼びます

I call my friend by their nickname on the sports ground.

私は運動場で友達をあだ名で呼びます

I call my friend by their nickname on the sports ground after school.

私は放課後に運動場で友達をあだ名で呼びます

I call my friend by their nickname on the sports ground with my classmates after school.

私はクラスの友達と放課後に運動場で友達をあだ名で呼びます