Hello,
The AFG1022 does not have an output for the internal modulation source. However since the AFG1022 is a two channel model you can use the second channel to imitate the modulation source using a ramp function.
That being said there are two caveats. The first is that align phase does not work, and the phase drifts when using a swept waveform. If you have access to an AFG1062 the phase does not drift, but you will still need to align the phase manually with a phase offset.