One day I received a text message saying that I was sued by the Hangzhou court. Is it true?/You don't say.

You received a text message saying that you were sued by the Hangzhou court. Such a short message must be fake. You need not worry too much.

If someone brings a lawsuit to the court, the court can find you personally, and will send you copies of legal documents such as the complaint directly or by mail, asking you to sign for it instead of sending a text message.

If there is only one short message that doesn't explain the identity and demands of the plaintiff to you, then it doesn't conform to the provisions of the procedural law, and the liar must be acting.