Ensure your project is at a standard rate like 44.1kHz or 48kHz for the best source quality before encoding.
A popular free tool, but it requires the FFmpeg library to be installed to export or import .m4a files. Recording jf.m4a
Use the pre-installed Samsung Voice Recorder or Google Recorder app. Recordings are typically saved in the .m4a format by default. Ensure your project is at a standard rate like 44