As his Republican rivals wrestle for attention at the fourth G.O.P. debate next week, Donald J. Trump will again be absent from the stage.

Instead, Mr. Trump, the party’s front-runner for president, will attend a fund-raiser next Wednesday for his super PAC, MAGA Inc., in Hallandale Beach, Fla., according to two people familiar with his plans.

The private event is a departure from Mr. Trump’s activities during the three previous Republican National Committee debates this year. Mr. Trump also did not attend any of those debates, but he held public counterprogramming events to draw attention to his own campaign. He and his aides have cited his dominating lead in the polls in calling on the R.N.C. to cancel future debates — a suggestion that committee members have not entertained.

Mr. Trump, who is running in the style of an incumbent president, continues to outpace his nearest rivals by more than 40 percentage points in most national polls. His absences from the previous debates have not dented his support, even as some of his rivals have criticized his nonattendance directly from the stage.

During the first debate in August, Mr. Trump promoted a taped interview with Tucker Carlson. In September, he spoke at a nonunion Michigan factory during the strike by the autoworkers’ union. And this month, he held a rally in Hialeah, Fla., at which he called the third debate, taking place less than 15 miles away, a waste of time.

The fourth debate, which will be held in Tuscaloosa, Ala., next Wednesday, is one of the final opportunities for the Republican candidates to build momentum before the early primary contests in Iowa and New Hampshire in January. It is expected to feature the smallest lineup this cycle: Several candidates who attended prior debates have dropped out of the race, and those who remain face heightened requirements to make the stage.

Candidates for the fourth debate are required to have a minimum of 80,000 unique donors, up from 70,000 donors for the most recent debate. They will also need to reach 6 percent — up from 4 percent — in two national polls or in one national poll and one poll in one of the four early states.

The official debate lineup has yet to be announced. But three candidates other than Mr. Trump are expected to qualify: Ron DeSantis, the governor of Florida; Nikki Haley, the former U.N. ambassador; and Vivek Ramaswamy, a wealthy entrepreneur.

Mr. Trump has gotten personally involved in the push to cancel the remaining debates, aggressively pressuring the Republican National Committee chairwoman, Ronna McDaniel, according to people briefed on the matter. She has declined to do so.

Maggie Haberman contributed reporting.