Nginx and Tomcat Setting for HTTPS

Recently, I got a new project.

The project is a still running website. They want to apply SSL certificate so it will have HTTPS instead of HTTP.

After checking their server, which is an EC2 instance. I found out they used both Nginx and Tomcat. I never used Nginx or know what is it. But after searching a while, I realized they used it as a Load Balancer for their multiple Tomcat Instances.

Being having zero knowledge about nginx. Now I'm confused where I should set up the SSL certificate ? Is it on the Nginx side or on Tomcat Side or even both ? My target for now is, as long as the user accessing it can have HTTPS then it is fine by me.

I have tried to search things out there. But seems cannot find a confirmation about this things.