Well, i think ideally, without using animation notifies, you would create a “Sound Cue” add different sounds and add a random play node, then you load an Audio component on Input Sprint Key, and add a “>” node(attach your player speed variable), and click into the > node add a speed (for instance 25), then when triggered, load the audio component (Play audio node). Inside the audio component you can add the sound cue.
If you look into the example SHOOTER GAME (Launcher content), the player character there has such a sound cue.