Another way to do that would be something like:
“I’ve used Fancy Filament PLA+ Very fancy edition. You can get them from the usual places, like their fancyfilament(dot)store. I also have an affiliate link which gives a coupon on purchase and I get a kickback. If you’d like me to send it your way, DM me please”
I think that’s within platform guidelines and requires consent from the user since they’d be the ones initiating the action.