I have a brass drain, rubber ring inner coupler compression ring, a fiber washer and a large rubber washer. Question, do I use plumbers puddy beneath the drain flange and the fiberglass shower and use the rubber ring on the bottom of the shower fiberglass with the fiber washer on top of the rubber, then the large lock nut?? Thank you very much in advance.

Fiber washer goes between rubber seal and nut.

Will this help? (see image)