ChatGPT powered features like context-aware translations are down at the moment. If this is inconvenient for you right now you could temporarily disable context-aware translations on the Settings page, which will at least allow you to continue getting translations:
UPDATE: This is now resolved but it lasted about 4 hours. For future reference you can check the status of the ChatGPT API which Readlang uses for AI powered features here: https://status.openai.com/