It does seem to be possible to order Certificates by post
https://www.gov.uk/government/publications/general-register-office-gro-certificate-application-forms#historyUnfortunately, you would need to print a form for each certificate application so as your printer is not reliable that may present a problem.
The GRO site
https://www.gro.gov.uk/gro/content/certificates/Login.asplets you order birth, death and marriage certificates online and will provide paper certificates via Royal Mail for any event, if that is what you want.
You do need to register on the site, then choose the option to Place an Order
Complete the details for each certificate you require and add each one to your basket till you have finished, then checkout to pay online.
NB as England has once again gone into lockdown the time frame for them to arrive by post will probably be longer.
Another option would be to contact the Registrar Office for the District in which the event occurred, and ask them if you can apply in writing but again the current situation will mean local registrars are trying to cope with fewer staff and may not be currently providing non urgent copy certificates.
If you decide to try the GRO website and get stuck, post back and someone will help to guide you through the process.
Boo