From the command prompt go to your app's root folder and execute:
tns plugin add @nativescript-community/ui-document-picker
only one function exported
export interface FilePickerOptions {
extensions: string[];
multipleSelection?: boolean;
pickerMode?: number;
}
export function openFilePicker(params: FilePickerOptions): Promise<{ files: string[]; ios?: NSURL; android?: android.net.Uri }>;