Nginx proxy\u pass SSL

我有一个wordpress网站在1台服务器上运行，我的移动应用程序的API在另一台服务器上运行。My domain.com指向网站服务器，我已将domain.com/api转发到我的api服务器。我有SSL的网站服务器工作，但不知道如何设置它的API服务器

在网站服务器上，我有以下nginx配置：

server {
    listen 80 default_server;
    listen [::]:80 default_server;
    server_name domain.com www.domain.com;
    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl http2 default_server;
    listen [::]:443 ssl http2 default_server;

    include snippets/ssl-domain.com.conf;
    include snippets/ssl-params.conf;

    root /var/www/website;
    index index.php;

    server_name domain.com www.domain.com;

    ...

    location ^~ /api {
            proxy_pass http://IP_OF_API_SERVER;
    }
}

server {
    listen 80 default_server;
    listen [::]:80 default_server;

    server_name _;

    location /  {
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-NginX-Proxy true;
            proxy_pass http://localhost:3000;
            proxy_ssl_session_reuse off;
            proxy_set_header Host $http_host;
            proxy_cache_bypass $http_upgrade;
            proxy_redirect off;
    }
}

在API服务器上，我有以下nginx配置：

server {
    listen 80 default_server;
    listen [::]:80 default_server;
    server_name domain.com www.domain.com;
    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl http2 default_server;
    listen [::]:443 ssl http2 default_server;

    include snippets/ssl-domain.com.conf;
    include snippets/ssl-params.conf;

    root /var/www/website;
    index index.php;

    server_name domain.com www.domain.com;

    ...

    location ^~ /api {
            proxy_pass http://IP_OF_API_SERVER;
    }
}

server {
    listen 80 default_server;
    listen [::]:80 default_server;

    server_name _;

    location /  {
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-NginX-Proxy true;
            proxy_pass http://localhost:3000;
            proxy_ssl_session_reuse off;
            proxy_set_header Host $http_host;
            proxy_cache_bypass $http_upgrade;
            proxy_redirect off;
    }
}

此配置正在运行，但我希望使用SSL连接到我的API