For generating a password you either need opt/apache installed to be able to use htpasswd -nBC 10 "" | tr -d ':\'; echo or use install contrib/python3-bcrypt and use /usr/lib/prometheus-node-exporter/gen-pass.py. Use the generated password hash to fill in the skeleton under /etc/node-exporter/config.yml.

Using tls

Generate a valid certificate according to the config.yml or use a proper one. If you use a self signed certificate you will make your prometheus scraper trust it.