Self-recovery passsword pricing

[YvonneP]

I just stumpled opon this feature and am extremly hyped by it, since we get around 5-10 requests to reset passwords per day.
Now I'm just wondering about the pricing.
We use 365, E1, E2 and E3 licences and only have the Azure pay-as-you-go subscription. We do not use azure on-prem.
Do you have an idea what additional costs would come with using the self-recovery feature?

[#2]

SSPR is included with all Office 365 plans. You need additional licenses only if you want to enable the password writeback (to on-premises AD) feature.