Callouts with a glow

Below is a picture with 2 callouts that have a glow/halo around the entire object in order to increase the visibility of the callout against the background picture.

I have figured out how to add a 3-point callouts and also change line thickness, color etc., but I don't see a 'halo' section in the 'Object Properties' dock, that would hopefully allow me to add the 'glow effect' all around a callout as seen below.

When I seach for 'halo' in Corel Draw Technical Suite help, nothing comes back !

Can anyone help with this one ? Thanks a lot in advance !