You can simply request that the door be changed to a glass door in the order notes at checkout. For example, include a note like this:

“Please change my 1-door blind corner wall cabinet (left side hinged with integrated filler) to a glass door frame instead of the regular door style.”

Please note that the cabinet interior will still be prefinished maple plywood, which may not be suitable for clear glass, as the interior color and wood type will not match your door material or finish.