What documents are required for applying for a marriage visa in Thailand after getting married at the Amphur?

The user has recently married and is unsure about the documents needed for applying for a marriage visa in Thailand. They are attending an appointment at the US embassy in Bangkok but are uncertain whether they have the correct appointment and what documentation is required, especially regarding notarization. A commenter questions the necessity of the embassy's involvement since the marriage was legally performed at the Amphur.