The property to replace. The syntax depends on the group's format.

JSON - dotted navigation, with quoting for keys that contain dots:

• Logging.LogLevel.Default - three nested objects
• Serilog.'MinimumLevel.Default' - a literal key containing dots
• Services[0].Url - zero-based array index

XML - the two .NET configuration collections only:

• appSettings.ApiUrl - the value attribute of the matching entry
• appSettings.BankApi:Key - colons and dots are literal here, never navigation
• connectionStrings.Default - the connection string
• connectionStrings.Default.@providerName - the provider name instead

Matching is exact and case-sensitive. Only entries directly inside the top-level appSettings or connectionStrings element are considered; entries inside <location> and external files referenced by file= are not.