Trump's official fundraising website:
It redirects you to a WinRed site paid for by the Trump Save America Joint Fundraising Committee, a joint fundraising committee composed of and authorized by Donald J. Trump for President 2024, Inc. and Save America (which is paying Trump's legal bills).
It doesn't get more reliable than this, short of walking up to Donald Trump himself and handing him a $100 bill.
Thanks for the info, check will go out tomorrow.