Including mime.types and clearing cache on docker did the thing.

events{
    worker_connections 1024;
}
http{
    include /etc/nginx/mime.types;
    server {
        listen 80;
        
        root /usr/share/nginx/html;

        location / {
            try_files $uri $uri/ /index.html;  
        }

        location /api/ {
            proxy_pass http://localhost:3000;  
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
        }
    }
}