Generally, a managing member of an LLC cannot speak for the LLC in court. The LLC needs to hire a licensed lawyer to do that.
The general rule is that entities may not represent themselves "pro se" through non-lawyer officers and must have a licensed attorney represent them in any court matter (in practice, a court will usually allow an officer or manager to write a letter to the court asking for a brief extension of time to a deadline to obtain a proper lawyer, even though that is logically inconsistent). If an entity does not hire a lawyer, a default judgment will enter against it.
In other words, a CEO or manager or managing member of a company isn't allowed to speak for it in court. This rule is almost universal in the world of legal systems descended from English common law, although sometimes there are narrow statutory exceptions.
The manager of an LLC is a person to whom legal process may be directed to begin a lawsuit, but that isn't the same as representing the LLC in court.
Wyoming does have an exception to the general rule for small claims court cases at Wyoming Statutes § 1-21-202(b), which states:
Notwithstanding the provisions of Chapter 5 of Title 33 of the Wyoming
Statutes, in small claims court, the state, governmental entities,
natural persons, corporations, partnerships, associations or other
organizations may litigate actions on behalf of themselves in person
or through authorized employees, with or without an attorney, provided
that if an attorney appears, the opposing party is entitled to a
continuance for the purpose of obtaining an attorney of its own.
Keep in mind, however, that small claims court only governs claims of $6,000 or less, and only in cases where the Plaintiff has elected to file a suit using small claims court procedures.
I note that this question is tagged "small claims court" but it isn't clear from the circumstances set forth in the question whether this is merely a claim for a small amount of money or is truly a claim that was filed using the special small claims court procedures in which an attorney is not required.
Wyoming Statutes § 33-5-101 et seq. is the law regulating attorneys which prohibits the unauthorized practice of law that is the basis for the general rule at Wyoming Statutes § 33-5-117 which states:
It shall be unlawful, and punishable as contempt of court, for any
person not a member of the Wyoming state bar to hold himself out or
advertise by whatsoever means as an attorney or counselor-at-law.
This statute isn't perfectly clear on its face, but is understood to codify the universal common law rule so it isn't ambiguous in any way.
