You’re correct, this code example is wrong. I will update the manual. Thanks for pointing this out.
It also looks like the underlying data for that station at that time has been archived. In the near future we will be updating our system to accommodate the data load we receive. At the moment, we can only handle requests going back about a year, but until then some of the older data will remain offline.
Meanwhile, this example will work:
from obspy.clients.fdsn import Client
from obspy import UTCDateTime
start_1 = "2019-10-01 00:00:00"
starttime = UTCDateTime(start_1)
endtime = starttime+600
client = Client(base_url='https://fdsnws.raspberryshakedata.com/')
waveform = client.get_waveforms('AM', 'R24FA', '00', 'EHZ', starttime, endtime)