I can not find the file gonfig.php, and install nano editor gives an error during installation.

Good day! I recently installed FreeNas and then added Nextcloud, now I need access to Nextcloud from the Internet. In the description I read that you need to edit the config.php file here and the problem. This file cannot be found. Nano editor not installing throws an error. The pkg updata -f command gives an error. Help how to find this file.