Heroku Discord.js ffmpeg

I wrote a discord music bot, and i used ffmpeg so that i put the executable in the botfolder, now i wanna push the bot into heroku, installed the npm package, but get this error in heroku:

2021-01-01T02:48:33.038447+00:00 app[Worker.1]: Error: FFmpeg/avconv not found!  2021-01-01T02:48:33.038488+00:00 app[Worker.1]:     at Function.getInfo (/app/node_modules/prism-media/src/core/FFmpeg.js:142:11)  2021-01-01T02:48:33.038489+00:00 app[Worker.1]:     at Function.create (/app/node_modules/prism-media/src/core/FFmpeg.js:155:38)  2021-01-01T02:48:33.038490+00:00 app[Worker.1]:     at new FFmpeg (/app/node_modules/prism-media/src/core/FFmpeg.js:44:27)  2021-01-01T02:48:33.038491+00:00 app[Worker.1]:     at AudioPlayer.playUnknown (/app/node_modules/discord.js/src/client/voice/player/BasePlayer.js:47:20)  2021-01-01T02:48:33.038491+00:00 app[Worker.1]:     at VoiceConnection.play (/app/node_modules/discord.js/src/client/voice/util/PlayInterface.js:71:28)  2021-01-01T02:48:33.038492+00:00 app[Worker.1]:     at play (/app/index.js:335:47)  2021-01-01T02:48:33.038493+00:00 app[Worker.1]:     at Client.<anonymous> (/app/index.js:143:17)  2021-01-01T02:48:33.038493+00:00 app[Worker.1]:     at processTicksAndRejections (internal/process/task_queues.js:97:5)  

https://stackoverflow.com/questions/65527029/heroku-discord-js-ffmpeg January 01, 2021 at 11:00AM