Why is this code not working it did in the past

extends CharacterBody2D

@export var speed = 300

func _physics_process(delta):
var horizontal_direction = Input.get_axis(“move_left”, “move_right”)
velocity.x = speed = horizontal_direction
move_and_slide()

explain why you believe this code isn’t working

you have two = in this line, you probably wanted
velocity.x = speed * horizontal_direction