Active Directory or LDAP are widely used to manage permissions and roles both in and outside the MS ecosystem (Entra seems to be AD rebadged), but requests are

Active Directory or LDAP are widely used to manage permissions and roles both in and outside the MS ecosystem (Entra seems to be AD rebadged), but requests are usually handled with a ticketing system (eg. Jira has "service desk" functionality, but other tools do as well). Most ticketing systems also integrate with email, and most would have a Slack bot too.