Using ACLs:

Since ACLs are an additional layer of authentication and are also stored in the database, using them has performance trade-offs. 

Not everyone will need them, so they are turned off(set to 0) by default. To enable, you need to set the environment variable CEI_NEXUS_ENABLE_ACLS to 1. For example:

export CEI_NEXUS_ENABLE_ACLS=1