I worked in that hotel for a month and then resigned. How can I get my salary back if my boss fires me?

First of all, there must be; If there is no labor contract or employment agreement, it is necessary to collect work facts and apply for labor arbitration to the competent department of labor and social security in the area where the enterprise is located.

Under normal circumstances, you can get the corresponding salary stipulated by law, and it is generally recommended to solve it first. Good luck.