legal ground
According to Article 162 of the Civil Code which came into effect in 202 1 1.
A civil juristic act carried out by an agent in the name of the principal within the scope of agency authority is effective for the principal.
Article 490 of the Civil Code
If the parties enter into a contract in the form of a contract, the contract shall be established when the parties sign, seal or press their fingerprints. Before signing, sealing or fingerprinting, one party has fulfilled its main obligations, and the contract is established when the other party accepts it.
A contract shall be concluded in written form as stipulated by laws, administrative regulations or agreed by the parties. If the parties do not do this in writing, but one party has fulfilled its main obligations and the other party accepts it, the contract is established.