Folder picker

You can use [options.initialDomain] to determine your predefined folder like userPictures

see: https://www.adobe.io/photoshop/uxp/uxp/reference-js/Modules/uxp/Persistent%20File%20Storage/FileSystemProvider/#getfolderoptions

Use a predefined custom path not work currently for security reasons: How can I get current user "Download" folder