Capacitor with Current Source in parallel with a resistor
I couldn't use the formula above and neither the Vc=Vi(1-e.....)
either since no resistor in series or voltage source.

1mA in parallel with 1 kohm in the fullness of time produces 1 volt, so change the current source (in parallel with the 1 kohm) to a 1 volt voltage source in series with 1 kohm: -

It's called source transformation and is related to Norton's and Thevenin's theorems.