When I need SSL certificates on my website, I purchase certificates from GoGetSSL.com. Most of my SSL certificates are Sectigo Positive SSL, previously called Comodo. It is a very good deal. $7.90 for two years. Back to my topic today, I like to use ECC SSL instead of RSA SSL.
It is a record of how I build an Nginx with Brotli compression and TLS 1.3 support. I use it on my Linode VPS. It is a Nanon type of VPS at Fremont, CA, USA. 1GB RAM, 25GB storage, 1 CPU. Ubuntu 18.04 LTS was installed on it.