Amos provides an integrated development environment (IDE) for CmdStan. You may choose not to use this IDE. The Stan files that are exported by Amos can be used in any Stan workflow. See the topic Open Windows File Explorer to learn about the Stan-related files that Amos exports. See the topic Ask where to save to learn where those files are located.
The CmdStan IDE can be opened from Windows File Explorer by double-clicking a file that has the stan extension.
The CmdStan IDE opens automatically each time you export a model to Stan if you have put a check mark next to View→Interface Properties→Stan→Open the CmdStan IDE.