Good day,
I would like to create a file in the language folder for certain plugins, unfortunately I did not find it in Google or Youtube, so I ask if someone can help me here?

Create a new directory under "oxide/lang" with the 2-letter ISO-639-1 language code. For example..

  en - English
  fr - French
  de - German
  pl - Polish
  ru - Russian
  es - Spanish

Then copy an existing Localization file from the default English folder, for example: "oxide/lang/en/PluginName.json" to the directory you created.

For example, if it is Spanish, then your new file would be in "oxide/lang/es/PluginName.json"

Then edit the Localization file and translate the English strings to Spanish.

Then reload the plugin. Now anyone who has Spanish as their language will see the Spanish messages.

Thanks for that, but I probably wrote it indistinctly.
The plugins do not have a file in the oxide / lang folder.
Write the question in more detail:
How do I create a file for the plugin that does not have a file in the oxide / lang folder.

//Yes, the plugins are on the server.

Plugins must support localization in order to be translated. If a plugin doesn't support localization, localization support must be added.  Developers can follow this guide for Oxide and this guide for uMod

This is what I was looking for, thank you. =)