You can collect coins without the lockscreen mode, but it is definitely more visible and easier with the lockscreen, and more motivating since you can manually collect the coins instead of letting it autocollect for you.
Melissa Kern
I went into my settings ans don’t see a Lock Screen mode
Emily Rose Hammond
Every 100 steps, you receive 1 coin. But you need to go under settings within the app here and turn on lockscreen mode.