Running Google Cirq example code from their webpage -- where do I find information about PROCESSOR_ID?

I’m just ttrying to run the simple example code in Google’s Cirq startup page:
https://cirq.readthedocs.io/en/stable/google/engine.html

I think I have the access authorized correctly via Google’s Console, but can someone help me understand where I would find the information for the PROCESSOR_ID? Thanks.

Code cut/paste from their webpage here:

import cirq
import cirq.google as cg

# A simple sample circuit
qubit = cirq.GridQubit(5, 2)
circuit = cirq.Circuit(
    cirq.X(qubit)**0.5,                 # Square root of NOT.
    cirq.measure(qubit, key='result')   # Measurement.
)

# Create an Engine object to use.
# Replace YOUR_PROJECT_ID with the id from your cloud project.
engine = cg.Engine(project_id=YOUR_PROJECT_ID, proto_version=cg.ProtoVersion.V2)

# Create a sampler from the engine
sampler = engine.sampler(processor_id='PROCESSOR_ID', gate_set=cg.SYC_GATESET)

# This will run the circuit and return the results in a 'TrialResult'
results = sampler.run(circuit, repetitions=1000)

# Sampler results can be accessed several ways

# For instance, to see the histogram of results
print(results.histogram(key='result'))

# Or the data itself
print(results.data)

for p in engine.list_processors():
    print(p.processor_id)