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Aerobase shows inventory https://aerobasegroup.com/part-number/88-22068_01-392-0319
BUT... if you are able to zoom in on the part, it calls out a CAGE code of 99135 which comes back to FLEXCO (https://cage.report/SAM/99135)
I would call them and see if they can sell you one direct. Otherwise...
I think the plug you are referencing is a mesh screen. That fill neck assembly should pull out (and twist to remove). That screen should not be plugged, its to catch trash in your fuel.