Is the text message from Hwaseong Law Firm true or false?

They are usually fake.

Regular law firms will not send you a text message telling you to sue you. They will either send a lawyer's letter or sue you directly.

If you receive a summons from the court, it means that you have been sued to the court and become a defendant. At this time, you should actively respond to the lawsuit in accordance with the court's instructions and legal regulations, and also use the law to protect your legitimate rights and interests.