buffrr

Creating a self-signed certificate for example.com (if you already have a certificate you can skip this step):

openssl req -x509 -newkey rsa:4096 -sha256 -days 365 -nodes \
  -keyout cert.key -out cert.crt -extensions ext  -config \
  <(echo "[req]"; 
    echo distinguished_name=req; 
    echo "[ext]";
 echo "keyUsage=critical,digitalSignature,keyEncipherment";