Export configuration of existing Azure AD Connect server
AADCONNECTAZUREENTRAENTRACONNECT
Open the Azure AD Connect tool, and select the additional task named View or Export Current Configuration. By default, the settings are exported to %ProgramData%\AADConnect. Settings are exported by using the JSON file format and should not be hand-created or edited to ensure logical consistency.
references: How to import and export Azure AD Connect configuration settings - Microsoft Entra | Microsoft Docs