A cloud-based identity and access management service for securing user authentication and resource access
@Ayano K Thank you for reaching out to us,
Is it possible for B2C to set a period of time during which passwords are not allowed to be changed? - Yes, it is possible via custom policy, this approach should help https://github.com/azure-ad-b2c/samples/tree/master/policies/password-history
Let me know if you have any further questions, feel free to post back.