To edit an existing TranslatePress language, input the language code and fill in only the columns you want to overwrite (e.g. Language name, Flag).<br>You can also add new custom languages. They will be available under General settings, All Languages list, where the URL slug can be edited.<br>For custom flag, first upload the image in media library then paste the URL.<br>Changing or deleting a custom language will impact translations and site URL's.<br>The Language code and the Automatic Translation Code should contain only alphabetical values, numerical values, \"-\" and \"_\".<br>The Automatic Translation codes can be found on <a href = \"https://cloud.google.com/translate/docs/languages\" target = \"_blank\">Google ISO Codes</a> and <a href = \"https://www.deepl.com/docs-api/translating-text/\" target = \"_blank\">DeepL Target Codes</a>.