Loki is banished from Asgard once again and must face his toughest opponents yet: the Simpsons and Springfield’s mightiest heroes. The God of Mischief teams up with Bart Simpson in the ultimate crossover event paying tribute to the Marvel Cinematic Universe of superheroes and villains.Source: TMDb
Currently, you can only stream The Simpsons: The Good, the Bart, and the Loki on Disney+ in the United States.
Unfortunately, you cannot buy or rent The Simpsons: The Good, the Bart, and the Loki on any of the streaming services in the United States at the moment.
The Simpsons: The Good, the Bart, and the Loki was released this year (2021).