Late to this, but for anyone still stuck: most of these cheap 4×6 printers (Munbyn, iDPRT, Beeprt, JADENS, Xprinter, Phomemo PM-241/D520…) speak the same language, TSPL - and the reason they “install but never print” is that the vendors only ship x86 binary CUPS filters. I got tired of that and wrote a free open-source driver: https://github.com/RunTheWall/tspl-cups-driver (apt/dnf repos, arm64/armhf/amd64, also shares the printer as AirPrint/IPP so phones print driverless via a Pi). Bench-tested on an HZD950-PRO; the other models are driven by the same verified TSPL command set but I’ll happily debug any that act up - there’s a printer-report issue template.