what you mean by "internal metronome" ?
there are two metronome types in qtractor for you to know about:
View > Options... > Audio > Metronome - when enabled this is what one might call as "internal"; though you have to supply your own audio sample files (eg. .wav) for each type of click (bar, beat); none is provided ootb. yet, you can check here for a couple of contributed metronome sounds;
View > Options... > MIDI > Metronome - when enabled this more like an "external" metronome; you'll have to connect through the designated MIDI output bus ports (ie. the first default "Master Out" when not set explicitly to dedicated output ports); you shall connect this to a proper MIDI instrument (a synth, sampler, etc.) that responds to the precise MIDI channel (default is 10) and bar and beat note numbers (default being76="Hi Wood Block" for bar-click and 77="Low Wood Block" as for the beat-click, named after GM Drum/Percussion key map);
what you mean by "internal metronome" ?
there are two metronome types in qtractor for you to know about:
hth.
cheers