Multiplex Does Not Run

After installing flatpak, I am presented with an issue when running as shown below:
```
[boo@bronny ~]$ flatpak run com.pojtinger.felicitas.Multiplex
panic: mkdir : no such file or directory

goroutine 1 [running, locked to thread]:
main.main()
	/run/build/multiplex/main.go:59 +0x59d
```

`Linux bronny 6.15.2-arch1-1 #1 SMP PREEMPT_DYNAMIC Tue, 10 Jun 2025 21:32:33 +0000 x86_64 GNU/Linux (i3wm)`