How to set own UID when using firebase auth

Ionic Framework ionic-v3
1

I used this code for signup with firebase auth

signUpUser(email: string , password: string){
	return this.fireAuth.createUserWithEmailAndPassword(email, password).then((newUser) => {
		//sign in the user
		this.fireAuth.signInWithEmailAndPassword(email, password).then((authenticatedUser) => {
			//successful login, create user profile
		this.userProfile.child(authenticatedUser.uid).set({
			email: email,
		});	
		});
	});
}

I need to create my own uid to manage students,i replace that uid to get my key as input.but if i replace that ‘‘uid’’ in the code it gives an error
saying

1st parameter cannot contain symols …

is it possible to create custom uid when using firebase auth???

i need to have my data like

image

here.If i dont use firebase auth this is possible.
but what happen when it comes with firebase auth???