A:
If the situation is as you have mentioned, that there is a fixed monthly profit for those who run the company, this is not permissible.
One of the conditions of the validity of a partnership is that the profits stipulated for the owner or workers should be a known portion of the profits, such as one third, one quarter, and the like, and the rest should be for the others. (Part No. 14; Page No. 305) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.