Troubleshoot-invalid-email-certificate

I would like to export my email security certificate to Thunderbird, I can not find an up to date guide for the latest version. The interface has changed since this guide was written…

Guide: https://support.avast.com/en-za/article/Troubleshoot-invalid-email-certificate

My question is how do I export my certificate for email client in the latest version?

Thanks in advance.

https://forum.avast.com/index.php?topic=224906.0