How to add/edit a DDF on Home assistant using text editor?

When I’m trying to install Nano:

bash: apk: command not found
root@core-deconz:~# apt install nano
Reading package lists… Done
Building dependency tree
Reading state information… Done
E: Unable to locate package nano
root@core-deconz:~#

I can see the json file, but don’t know how to modify…