Is the money earned by brokerage halal?

A friend of mine has collected the phone numbers of people who can take care of old or sick people and finds clients for these people. In other words, it brings these caregivers together with people who are looking for caregivers. In return, he receives half of the first month's fee as a commission. As far as I know, if there is no risk in the trade, that profit is not halal. Is this money received by this person halal?