The audio bitrate is kinda low under standard common requirements and im not sure if it's allowed to have a 128 kbps bitrate.192 kbps is always the best option.I would recommend to contact some ppl who associate with mp3s and stuff and give you a better mp3.https://osu.ppy.sh/help/wiki/Ranking_Criteria
The song's audio file must be of reasonable quality. Try and source .mp3 files yourself; ripping them from a streaming video site often results in low quality audio with high file sizes. The bitrate of a beatmap's audio file must be no lower than 128kbps and no higher than 192kbps. If you are having trouble acquiring an appropriate audio file, contact one of the more audio-savvy BN; they will be more than happy to help find an .mp3 for you.
I understand your concern so I will keep that in mind (Bcs better audio quality is a good thing to have) but by the ranking criteria rules, 192kbps is not required.