He might run, or he might decide to settle for being the kingmaker and senior statesmen. There is no way he can unify the Republicans, and running without a strong party behind him will result in the Democrats winning (unless they also fragment).
Trump also may allow his views to evolve, e.g. switch from isolationist to hawkish leader of the free world. A lot his views on domestic issues may prove a problem unless he apologizes and says his views have been revised to reflect changing conditions (declaring a state of emergency for Covid, opposing immigration during a period of serious labor shortages). Instead of complaining the election was stolen, the Republicans need to both argue for more security in voting and making a serious “turn out the vote” effort for mail-in ballots.