Is it permissible for a partner in a commercial shop to increase his fixed monthly allowance without the knowledge of his partner if it is not sufficient for him?

It is not permissible for a partner's share in a company to be a fixed amount of profit; rather, it must be a common percentage of it, otherwise, the partnership becomes void. So, if a partner specifies a known amount for his brother as profit, this is not valid, and this partnership must be invalidated, and they must agree on a common percentage for each of them. If one of the partners performs additional work that is not required of him by virtue of the partnership, he may receive a monthly wage or an increase in his percentage of the profit. What has been agreed upon must be adhered to.