aws_ssl.txt

Add a self-signed SSL certificate using OpenSSL
Install OpenSSL and create the /etc/nginx/ssl directory:

sudo apt-get install openssl
cd /etc/nginx
sudo mkdir ssl
Then, we create the self-signed SSL certificate using this command:

sudo openssl req -batch -x509 -nodes -days 365 \
-newkey rsa:2048 \
-keyout /etc/nginx/ssl/server.key \
-out /etc/nginx/ssl/server.crt
After that, we add this certificate to our server block configuration:

cd /etc/nginx/sites-enabled/
sudo nano fastapi_nginx
Inside the file we make the following modification:

server {
    listen 80;
    listen 443 ssl;
    ssl on;
    ssl_certificate /etc/nginx/ssl/server.crt;
    ssl_certificate_key /etc/nginx/ssl/server.key;
    server_name 18.116.199.161;
    location / {
        proxy_pass http://127.0.0.1:8000;
    }
}
We save that file (Ctrl X) and then restart Nginx:

sudo service nginx restart
Finally, we run our API:

cd path/to/Deploying-FastAPI-using-Nginx
python3 -m uvicorn main:app
If everything works correctly, you should now be able to access your server over HTTPS (https://{your EC2 public IP}/).
Your web browser (in this case I am using Firefox) may display a warning