Exploratory’s get_sentiment function supports only English, but if you want to do sentiment analysis with other languages, sentimentr R package, which get_sentiment function internally uses, has the feature to work with other languages of similar grammar as English to some extent by giving appropriate dictionaries to the sentiment function.
In the document, there is an example with Danish.
So, directly calling their sentiment function with your custom function could be a candidate for your sentiment analysis solution for other languages.