Setting up languages for multi-language fields
Using the "Multiple Languages" field types for Text, Markdown text and HTML, ACF supports having custom fields dynamically show different content depending on your visitor's language.
Before you can edit content for multi-language fields, you need to tell ACF which languages to handle content for and optionally provide a DeepL API key for built-in translation.
So, from your ACF dashboard, click the "Open settings" button to open the settings dialog:
In the selection box for "Multiple languages setup", select the languages you need to provide content for. You can select as few or as many languages you need. Note that languages can be added or removed dynamically, so you don't need to know your complete setup before adding content for each language. If you need to add a language later after setting up content for other languages, you can just do so.
Mind the ordering as this will be reflected in the editor. You can also use the ordering to provide a default language in case a visitor's language is not defined (see related article below)
When you edit a multi-language custom field, the ACF editor will allow you to input content for each language selected in the above setup.
Here is an example of a multi-language text field called "Greetings", allowing input in all three defined languages:
Please see related articles below for how to set up translation services within ACF.