Benito Antonio MartÃnez Ocasio--stage name Bad Bunny--posted a story to his Instagram account @badbunnypr that featured this video by Kamala Harris's account. The story has since expired, and I was only able to find one screenshot of the story.
I found multiple other news stories either claiming Bad Bunny supports VP Harris or mentions his Instagram story, including https://apnews.com/article/harris-bad-bunny-latino-vote-18ed2c1307264f2651ab4375d4b5070d https://www.cnn.com/2024/10/31/politics/celebrity-endorsements-puerto-rico-harris-trump/index.html https://www.cnn.com/2024/10/27/politics/bad-bunny-kamala-harris-puerto-rico/index.html and https://thehill.com/blogs/in-the-know/4959298-bad-bunny-puerto-rico-msg-trump-rally-tony-hinchcliffe/
While multiple sources have stated Bad Bunny supports Harris, the Instagram story does not include any statement clearly verifying his support of Harris, and none of the articles I have found the name of Bad Bunny's representative who they're citing. The Kamala Harris video that Bad Bunny shared includes Harris talking about the issues Puerto Ricans face, including issues Bad Bunny has spoken on in the past like the electrical system and federal relief following Hurricane Maria. Due to Harris's statements aligning with Bad Bunny's statements, it is safe to say he supports Harris's potential policies. Additionally, he posted this video captioned "garbage" in response to a comedian at a Trump rally calling Puerto Rico "a floating island of garbage in the middle of the ocean". This 8-minute long video celebrates Puerto Rican icons and culture. The video ends with a message in Spanish that essentially says Puerto Ricans are fighters and will remind anyone who forgets that fact. Due to this message and its position as a refutation of the statements made at the Trump rally, it's also logical to assume Bad Bunny is anti-Trump and that his statement about Puerto Ricans being fighters implies voting for Harris as a fight against Trump.
Overall, there isn't enough clear evidence on whether Bad Bunny supports Harris or if he only supports voting for Harris as a fight against Trump. Until Bad Bunny or a clearly named representative makes a statement confirming his support for Harris, any claims of Bad Bunny supporting Harris would be exaggerated or at least partially misleading.