Am a Nigerian I need to work as a security hero in...

We would like to inform you that according to the Foreigners Residence Law, an expat may not be employed for a visit until after obtaining a work permit and amending the status through the Federal Authority for Identity and Nationality. After that change the visa to work and if you join the work of that company before adjusting the situation then this is violation by you and the company and you will face legal issues.
As the law states:
 If the visa is for a visit, the foreigner is not entitled to work anywhere in the country, whether paid or unpaid, or as an employer. The Federal Authority for Identity and Nationality shall approve this and the expatriate shall be punished by imprisonment for a period not exceeding three months and a fine not exceeding 10000 AED or one of these two penalties. The court shall order the deportation of the violator from the state and a fine of 50000 AED shall be imposed on any person who used a foreigner without his sponsorship without complying with the conditions and conditions prescribed for transferring the bail or without obtaining the necessary permit for that.