Give a free month

There are a couple different options for giving users free days/months. You can set a "Trial Period" when users sign up where they can use the product for X number of days before they are required to subscribe

https://spark.laravel.com/docs/3.0/billing#no-credit-card-up-front

If users are already subscribed and you want to give them free months, you can give them a free month yourself by editing their profile and adding time to their subscriptions or you can give them coupon codes to add themselves in their profile.

I will check the coupon codes solution ! Thanks a lot !!

Coupon codes work the best for current customers because its very easy to track by name of the coupon. That way you can better analyze your data.

I must create the coupon in Stripe ?

Yes. Then, they can apply or you can apply the coupon. I usually name the coupon based on how it affects income, support or marketing campaign.