Want to run this Docker container locally?

 docker run -d -p 5666:80 --restart always --name ctf-json-post joshbeck2024/ctf-json-post

The webpage is abundantly clear.

• Post JSON.
• Get Flag!

curl -X POST <http://localhost:5666/index.php> \\-H "Content-Type: application/json" \\-d '{"flag": "give_me_flag"}'