raspberry pi as flash drive

Question

linux

I bought www.dension.com/product/3G-USB-internet-modem/dension-webradio - it doesn’t work, or rather it works, but playback is constantly interrupted, although if you listen on a phone with the same SIM card, then there are no interruptions.

Webradio has an interesting implementation - it appears to be an ordinary flash drive with ordinary mp3 files, if you start playing these files, for example, on a car radio, then Webradio transmits a webradio mp3 stream to them.

I am looking for how to do the same, only with raspberry pi, so that when connecting the board to a PC (for example), the board would recognize it as a USB flash drive.