If you have been asked to get tested by your education establishment as a close contact but display no symptoms you must still book at PCR test via GOV.UK. Select the "you have been requested to get a test" option.
PCR tests should be completed 5 days into your isolation 10-day period to ensure you can return to your education establishment after the isolation period. This can be a postal PCR test which should be posted in a priority post box and your results will be emailed or text to you within 48 hours.
More testing information