Some of services still using basic auth. For generate credentials for webserver (apache/nginx) need to use special utility – htpasswd

At first, install htpasswd. For Debian based distributive command for apt: sudo apt-get update && sudo apt-get install apache2-utils

After installation for create new file with credentials use: htpasswd -c credentials.passwd user_name

For existing file just run: htpasswd credentials.passwd user_name new_user_name

After this created file credentials.passwd can be used for Nginx or another services.