You can order it using the pay-per-use model and its licensing is free.
Fldigi is an easy-to-use freeware application that is characterized by its simplicity, flexibility and compatibility with numerous digital modes. It facilitates the analysis of speech waveforms to extract information directly from an audio signal and make the most of the useful elements with which the amateur radio operator is already familiar. The program can be used to check all the classical modes such as FM, AMS, L 66c