I just want to know regarding resignation under...

The UAE Labor Law only granted the employer the right to terminate the employment contract during the probationary period without notice or remuneration and the probationary period shall not exceed six months, i.e. the employer may terminate the employment contract without giving the worker a period of notice or payment of any dues.
If the worker terminates the work contract illegally, he must pay compensation to the employer, and the value of this compensation is a maximum month and a half salary.
There is no legal text obligating the worker to pay the value of the visa if the worker terminates the work contract.
Here is the text of the UAE Labor Law regarding your inquiry:
Article 37
The worker may be appointed under probation for a period not exceeding six months and the employer may dispense with the services of the worker during this period without warning and without end of service reward. The worker may not be appointed. Under experience more than once with one employer, and if the worker successfully passed the period of the experiment and continued to work, the period of service shall be calculated.