I doubt this is right way if the test email attached PDF explicitly asks you to contact IRCC before giving the test outside of Canada.
My test email PDF, Eligibility section explicitly stated that -
If you are outside of Canada and you would like to take the Canadian citizenship knowledge test
from outside of Canada, please contact us (
CIC-OTTAWA-CITIZENSH@cic.gc.ca) within 24 to 48
hours from the date of this notice and indicate ‘’Outside Canada’’ in the subject line of the email.
Provide your name, application number and the start and end date for your online test in the text of
your email. We’ll contact you with the next steps after we receive your email.