You're welcome.
I hardly ever see them offered for sale.
I'd start by trying FN directly.
Then MGW:
https://www.midwestgunworks.com/fn-scar/complete-trigger-module.html(They list FN's part numbers here.)
Then finally maybe hi-desertdog.com (call them) but they'll be sky high, and may only offer their in-house aluminum version.
Last time I saw their select-fire SCAR 17 bolt carrier, it was just a formerly semi-auto one they welded up themselves. (They didn't explain that in their description either.)
You might be able to buy another aftermarket aluminum version and convert it instead. (Never seen that in person though.)
If you call Geissele they may sell you their select-fire version of the Super SCAR hammer & trigger. (The regular one is not compatible.)