Legal analysis: 1, yes, and the official seal is generally required. It depends on whether the power of attorney of that legal person clearly indicates that it needs the signature and seal of the legal person. If there is an explanation, it must be signed by the legal person and stamped with the company seal. If the legal person is absent, it can also be directly stamped with the private seal of the legal person.

2. A company as a legal person is an independent organization that can take responsibility in its own name, and is fully capable of carrying out civil legal acts in its own name, including authorized acts, and the act of entrusting an agent in its own name takes legal effect.

3. Authorization is a unilateral legal act, and agency certificate, as its manifestation, has independent probative power.

Legal basis: People's Republic of China (PRC) Civil Procedure Law.

Article 48, paragraph 2: A legal person shall be represented by its legal representative. Other organizations are sued by their principal responsible persons.

Article 59, paragraph 1, where a person entrusts another person to represent him in litigation, a power of attorney signed or sealed by the client must be submitted to the people's court.