How to apply qatar visa

Kindly be noted that in order to obtain a Qatar visa in general and to work in particular, the following conditions must be met to obtain the visa:
Holding a passport, valid for a period of six months
Having an employment contract in one of the companies in Qatar
No crimes or violations done by you in Qatar
Security approval from the authorities that you are entering for work
Medical examination statement

For entry to work in Qatar, it is required to obtain an entry permit for work, which is granted only according to a work contract concluded with its applicant according to the terms and conditions prescribed by law and it is forbidden to relinquish the conditions to others or dispose them in any way or exchange them by others, whether the assignment or disposal or trading with or without in exchange for money or not. The employer is responsible for the residency of the expatriate worker in Qatar, and the worker is prohibited from working for another sponsor without the sponsor's written consent.

The law of regulation on Expatriates' entry

Article 16
An expatriate who has been authorized to enter or reside for a specific purpose, or to work for a specific entity / company, must not violate the purpose for which he / she was authorized to practice, OR to leave work with the employer, or to work for an agency that he / she is not allowed to do so.
It is not inconsistent with the purpose of the residence permit for the expatriate to practice, even with the approval of the competent authority, some of the businesses in the company which he / she is a partner or authorized to sign for it.