That's not quite the way we do it.
Our fascia and rimjoist are one and the same. In our case 2x12 select heart or better redwood.
We then take your trim piece and rotate it verticle and cover the seam between the decking and the fascia.
I would post a drawing or a pic, but I don't know how to do it. But I can link a pic.
Here is a link that might be useful:
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step detail
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