An FLP file contains no actual audio data on its own. If you share an FLP file without its associated samples, the person receiving it will hear silence when they open it. That's why FL Studio has a "Zipped Loop Package" feature, which bundles the .flp file with all its referenced samples into a single .zip file for easy sharing.
Open the piano roll, choose a VST (like Serum or FL Keys), and apply it to the MIDI notes. mp3 to flp converter online
Here are the most popular methods:
Forget the fake converters. Here is the real 10-minute guide to building an FLP from a downloaded MP3 using free online tools + FL Studio. An FLP file contains no actual audio data on its own