My testing server has the following functions:

I want to draw a polygon and add the new polygon to this layer, but all the property canCreate/canDelete/canUpdate/canUpdateGeometry return NO, and of course, I failed to add graphic to this layer. Is anything I missing?
AGSGraphic *newGraphic = [AGSGraphic graphicWithGeometry:self.sketchLayer.geometry symbol:[self getMapSymbolByType:eIfosMapSymbolTypePolygon] attributes:@{@attire:@testttt, @attr2:@test22}];
AGSFeatureLayer *inspectionLayer = [AGSFeatureLayer featureServiceLayerWithURL:[NSURL URLWithString:LAYER_URL_STR] mode:AGSFeatureLayerModeSnapshot];
inspectionLayer.editingDelegate = self;
// return NO
if (inspectionLayer.canCreate) {
NSLog(@can create);
}
// return NO
if (inspectionLayer.canDelete) {
NSLog(@can delete);
}
// return NO
if (inspectionLayer.canUpdate) {
NSLog(@can update);
}
// return NO
if (inspectionLayer.canUpdateGeometry) {
NSLog(@can update geometry);
}
[inspectionLayer applyEditsWithFeaturesToAdd:[NSArray arrayWithObject:newGraphic] toUpdate:nil toDelete:nil];