The 2024 election has not been conducted.
Every aspect of the conduct of an election has the right to be inspected. Every candidate has the right to challenge election results and to present areas where there are unequal standards applied, lack of access and transparency in conducting the collection and counting of ballots, and then some. Neither Donald Trump NOR Joe Biden should be agreeing not to contest the outcome of an election any more than Coke Stevenson should have agreed to not contest the outcome of the 1948 Texas Democratic Primary for Senate.
No candidate for ANY office is required to concede defeat or congratulate the victor. No candidate for ANY office is required to state that an election was conducted fairly, because not every election in American History has been conducted fairly. It's simply not required, and the electorate can judge for themselves what they think of the candidate not accepting an election result.
Every candidate has the right to institute legal challenges to the result, and every challenge deserves an honest hearing on the merits. Presidential candidates do, indeed, have a right to challenge the naming of slates of electors; 2024 was hardly the first time it has been done.
These are RIGHTS that extend not only to candidates, but to voters. No candidate should be elected with the votes of dead people, non-citizens, persons voting twice, stuffed ballot boxes (by any method), etc. Indeed, I believe that any candidate has a moral duty to its voters to challenge, by all means at his/her disposal, an election that they have reason to believe has not been conducted fairly, honestly, and/or lawfully. Stolen Elections are a part of our history, and controversies as to the Electoral votes are part of our history (1824 and 1876). No one is obliged to roll over and be hosed.
All of which is beside the point.
If the 2024 Presidential election is free and fair, but does not result in a win for the Republican nominee, will Republicans accept the result, or attempt to seize power by fraud and force?
I don't expect them to, and Senator Scott's answer strongly implies he, at least, will not.
