Is there anyone who does the work and materials to solder the electronic components to the pcb board?

Yes, there are some companies that specialize in welding for you. You can prepare the materials yourself, or you can contract the work and materials from these companies. The two parties will negotiate specific methods. There are also specialized supporting companies that will prepare materials for you in batches. Great discount. You just spend money and that's it. The specific details must be considered, how to inspect, accept, the responsibilities of both parties... etc. It is not easy and must be considered in advance.