Can't point you to the screen number since I'm away from my computer.

On the input for MA Part-Year/Nonresident Info, you'd find the toggle for Filing Massachusetts 1-ES for 2020 as resident.

You should also be aware that Lacerte will, by default, compute ES-Tax based on PY liability.  Since prior year exception does not apply to part-year residents, you should annualize the income for ES-Tax projection.