Would the salary be unlawful (haram) or have a doubtful aspect (shubha) if a pharmacist works as the person responsible for supplying a health center with medications, and their workdays are only one or two days a month, depending on the availability of orders?

There is no objection to an employee's work if he is authorized to appoint staff and distribute tasks. The employer has the right to utilize the hired person for all tasks that are within the nature of his work and capacity, and to define the hire by a specific time or a specific task. Hiring is divided into two types: either for a known duration or for a known task. Accordingly, the salary is permissible.