Trump Sort of Maybe "Concedes"(?)
Trump has directed Emily Murphy of the GSA to "do what needs to be done with regard to initial protocol". Or, in other words, to begin the transition to a Biden presidency. Emily Murphy's letter to Joe Biden is a bit unusually worded, but the implications are clear. Pursuant to the Presidential Transition Act of 1963 (see Notes), the GSA is put in charge of "ascertaining" the "apparent successful candidates" for presidency, and accordingly releasing earmarked funds to help with the transition to a new administration. The goal of the act was to understand that, in a modern era, presidents can't just hit the ground running on January 20th, but it understandably puts the head of the GSA in a very awkward position.
The letter spends a lot of time on how it is inappropriate for the GSA to be put in this position, especially when legal disputes are pending. It's a point I'm sympathetic with. Why I say it's unusually worded is that Murphy never refers to Biden as the "apparent" winner of the election, but instead just states "because of recent developments involving legal challenges and certifications of election results", Biden is receiving this letter. Compare, for example, to the letter Barack Obama received from the GSA on Nov 5 2008:
I am very pleased to inform you that pursuant to the Presidential Transition Act of 1963, as amended, 3 U.S.C. § 102 note (the "Act"), I have ascertained that you and Senator Joseph R. Biden, Jr. are the apparent successful candidates for the offices of President and Vice President respectively, and that you are therefore the President-elect and Vice President-elect for purposes of the Act. Consequently, pursuant to Section 3 of the Act, you are entitled , upon request, to receive necessary services and facilities for use in connection with preparations for the assumption of your official duties as President and Vice President.
Language and vocabulary quibbles aside, Trump is on record as having directed the head of the GSA to release transition funds to Joe Biden. Legally, this can only happen if the head of the GSA ascertains Biden as the apparent winner of the election. Also legally, this is not required to happen and rests solely at the discretion of the GSA. So it didn't need to happen, but Trump asked for it to happen.
I think this is as close to a concession that you're going to get from Trump.
Of course, the ultimate coup would be for Trump to get plastic surgery and holograms to look and sound like Joe Biden, and kidnaps the real one and stores him in one of Epstein's secret islands.