What is an alternative to creating /etc/sysconfig/dropbox if /etc/sysconfig doesn't exist?

Thanks in advance for the help. I'm a newb when it comes to system files. I'm trying to install headless dropbox on my ubuntu 21.04 machine that is running i3. I'm using this tutorial.

When I got to the last step under the section on creating a system service I found out that my machine doesn't have /etc/sysconfig. The tutorial wants me to create the file and put DROPBOX_USER= "USER" in it. Should I just create the missing directory and put the file in it as instructed, or is there an alternative method that I should be using?