They're both volunteers, and not attorneys of record. They don't get paid for their efforts, and their names won't be on the filings as an attorney of record (they may appear as affidavits).

Rudy is Trump's personal attorney and is acting as his attorney of record for his campaign. Jenna Ellis is his legal advisor - but also not an attorney of record.

Attorney of Record refers to a lawyer who has appeared in court or signed pleadings on behalf of a party to a suit. The Attorney of record is the person entitled to receive on the party's behalf all pleadings and documents from the court as well as other parties.

That's all. Big lawsuits can involve tens if not hundreds of lawyers researching and gathering data, who's names won't appear on the filing or appear in court.