Since LiDAR has been built into the newest 2020+ iOS devices (iPhone 12 Pro, iPad Pro).
ARKit has more possibilities than ever, including support for exporting to .obj.
Here is the code for exporting a ARReferenceObject to .arobject
guard let testRun = self.testRun, 
      let object = testRun.referenceObject, 
      let name = object.name 
else {
    print("Error: Missing scanned object.")
    return
}
    
let documentURL = FileManager.default.temporaryDirectory
                             .appendingPathComponent(name + ".arobject")
    
DispatchQueue.global().async {
    do {
        try object.export(to: documentURL, 
                previewImage: testRun.previewImage)
    } catch {
        fatalError("Failed to save the file to \(documentURL)")
    }
}
How do you export as .obj?