SSL cert

how can I generate the files needed to create an SSL certificate for say COMODO or SECTIGO?

who do you generate the files needed to get the cert and then where do you put them once you are done.

I want to do this instead of lets encrypt or self signed.

Thanks in advance for any help.

Create a Certificate Signing Request (CSR):

openssl genrsa -out domainname.key 2048
openssl req -new -key domainname.key -out domainname.csr -sha256

After signing the certificate, place certificate an key in: etc/grommunio-common/ssl/
Name the files as:

/etc/grommunio-common/ssl/server-bundle.pem
/etc/grommunio-common/ssl/server.key

server-bundle.pem contains the certificate and the CA (chain) file.
Restart all SSL services or restart the server.