If you have a Target or Dollar General nearby, then you can grab a free Febreze Plug Warmer! For Target you'll want to use their $3/1 Circle coupon. Some zip codes have this priced at $2.99, but a few others I entered priced the warmer at $3.19, so you might have to pay a quarter.
Both of these freebies expire on 7/3/21.
Finally, if you prefer shopping at Walmart, then you can use this promo to get a free Febreze Plug Warmer by July 26!