HSE have extended current First Aid extensions during Covid
FAW or EFAW certificates that expired after 16 March 2020 can remain valid until 31 October 2020 or 6 months from date of expiry, whichever is later. All requalification training for these certificates should be completed by 31 March 2021.
https://www.hse.gov.uk/coronavirus/first-aid-and-medicals/first-aid-certificate-coronavirus.htm#qualifications