how to show all console.log from node.js in heroku?

From the heroku doc:

The logs command retrieves 100 log lines by default. You can specify
the number of log lines to retrieve (up to a maximum of 1,500 lines)
by using the –num (or -n) option.

$ heroku logs -n 200

So probably you need to request more lines with -noption.

As per comment received, you can also stream the current log with:

$ heroku logs --tail

Please look at the doc