Try something like this to create milti records in single query:
curl -X POST -H "QB-Token: 281a7bc7c2984763ce77cda1b3641e551b93f887" -d "record[1][Platform]=...&record[1][Course_Name]=...&record[2][Platform]=...&record[2][Course_Name]=...&record[3][Platform]=...&record[3][Course_Name]=..." https://api.quickblox.com/data/tblCourses/multi