❔ How to read configuration based on environment

public string GetConnectionString(string service)
{
    var _tenantSettingsKey = _shellSettings.Name + ":" + service;
    var _defaultSettingsKey = service;
    var connectionStringSettings = ConfigurationManager.ConnectionStrings[_tenantSettingsKey] ?? ConfigurationManager.ConnectionStrings[_defaultSettingsKey];
    if (connectionStringSettings == null)
    {
        throw new ConfigurationErrorsException("A connection string is expected for " + service);
    }
    return connectionStringSettings.ConnectionString;
}