What UAE labour law says about unpaid overtime and proof of extra hours

Question: I work at a hotel, 9 hours daily according to my contract. My employer requested me to work 10 hours a day during the summer time and assured that I would be compensated for the additional overtime hours. I agreed, but he refused to pay arguing that there was no written agreement between us concerning the additional working hours. Is the employer entitled to do this? What legal action should I take in these circumstances?
Answer: According to Article (19) of the Federal Decree Law No. 33 of 2021, the employer may instruct the worker to work overtime over the normal working hours, provided that they do not exceed two hours per day. The worker may not be instructed to work for more than that period, except in accordance with the conditions and rules specified by the Implementing Regulation hereof. In all cases, the total working hours shall not exceed (144) one hundred and forty-four hours every (3) three weeks.
Having no written agreement regarding working extra working hours means that the burden of proof lies on you, to prove that the additional working hours were performed at the employer's request, with the employer's knowledge and approval. Such evidences may include WhatsApp messages, SMS messages, emails, or other written communications from the employer, Work schedules, attendance records, time sheets, instructions, assignments, or work-related communications issued during the additional working hours; and any other documentary or electronic evidence establishing that the additional working hours were performed at the employer's request and with the employer's knowledge.
So, you have to file a complaint in front of the Labor office and the court will assess the submitted evidences and render the judgment.