My 2002 Gen2 Subaru Forester didn't have the plastic handle on the fuel trap lever when I got it.
I have no idea what this handle looks like from the factory, I just did mine to fit the lever and feel ok when pulling on it.
The handle just clips on the lever, no need to glue it or use any spacer.

I guess you can use the handle on Subaru Outback, Forester and other Subaru models around 2002-2006. You can measure the lever of your Subaru and compare it to the one I made on CAD to know if yours is the same as mine.

I sanded the part. Then with black acrylic paint and a top coat it looks better.

Part has been designed on Solidworks 2018, files are available to download.