How to use node js and python on same domain?

Docker is the best option. Use docker and create three container (nginx, nodejs, Webapp2).

for nodejs, use port like 8080
for Webapp2, use port like 8000

links nodejs and Webapp2 with ngninx in docker-compose.yml and configure nginx.conf file.

Use nginx.conf like

location /dashboard {
    proxy_pass http://nodejs:8080;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}
location / {
    proxy_pass http://webapp2:8000;
    proxy_set_header Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}