Installing HTTPS on Tomcat 7 with CentOS

Unfortunately, I don’t have anything in /etc/letsencrypt/live. In my other server I do, but I’m not sure it would work if I only copied the files from one server to another. There I have a file called “MyDSKeyStore.jks” that I made using this method.
I copied it to my CentOS server just to see what happens and I’m getting this message saying my certificate is not safe:
Sem%20t%C3%ADtulo