Hi Michael,
It's unclear to me what you're asking.
If you're asking about the maximum current output of the AFG1022, then this is implicit in the datasheet.
It says it has a max amplitude of 5 Vpeak into 50 Ohm loads, which implies a max current of 100 mA. For a load with lower impedance, the datasheet isn't clear, but we could assume it is doubled for an ideal 0 Ohm load (due to the fact the AFG1022 has an output impedance of 50 Ohms).