[keycloak-user] Custom Account implementation and In-App Password changes

Hi, is there any API for implementing custom version of UserAccount? We are going to create separate User Account app for our users where they could manage their data (names, telephones etc.), passwords and company-specific settings. Almost all of per-user management except OTP could be implemented via calls to Admin REST API, but it seems a little hacky. So is there any suggestions or experience about creating substitution for out-of-the box Account app?