#20 ui_mainwindow.ui or ui_mainwindow.h is missing from source

[Zirneklitis]

mainwindow.h:26:10: fatal error: ui_mainwindow.h: No such file or directory
26 | #include "ui_mainwindow.h"
| ^~~~~~~~~~~~~~~~~
compilation terminated.
make: *** [Makefile:576: main.o] Error 1