1-contract theory: fulfillment is a contract due to its legal nature. The practical result of this view is that the person who will perform must have a contractual driver’s license. As a rule, he must be fully qualified. A person who is not fully qualified will not be able to fulfill the debt.

2-material action theory: it is a material action in terms of the nature of fulfillment. Because there is no contract or legal action, the person who will perform the fulfillment will not be required to have a driver’s license or have a full driver’s license.

3-Limited contract theory: it is a conciliatory theory and also dominates the doctrine. In this theory, a distinction is made when explaining the legal nature of fulfillment. Accordingly, if the agreement of the parties, agreements, that is, legal action is needed for the fulfillment of the debt, the performance is a contract in terms of its nature. As a result, according to this theory, the person who will perform must be fully qualified. This does not create a change in the case of rights. After the contract is made, the savings must be made.