If your database uses a custom schema name for the Operational and/or Configuration Store other than the default 'dbo', you must configure the
OperationalStoreSchemaName setting and/or
ConfigurationStoreSchemaName setting with your chosen schema name. It's important to note that this custom schema setup will not be compatible with Configuration, ExtendedConfiguration, and Operational migrations.
If you are using the default Identity Store (AspNet) run this script. If you are using a custom Identity Store this step is not needed.
You have to manually adjust the SQL script specific to migrate IdentityServer to AdminUI. Here, you must replace any 'dbo' string with the given schema name to your Configuration Store. Also, you might need to remove any modifications to the migration history table in the script, as this table may not exist in your database.
At this point you should be able to run AdminUI.