A timely report out from Congressional Research Service on Presidential Transition Act: Provisions and Funding:"The constitutional transfer of power & authority from an incumbent American President to a successor is a momentous occasion in American gov't."
https://crsreports.congress.gov/product/pdf/R/R46602

CRS: "The Presidential Transition Act of 1963 (PTA) authorizes funding for the General Services Administration (GSA) to provide suitable office space, staff compensation, and other services associated with the presidential transition process."

CRS: "Once the President-elect and Vice President-elect have been ascertained by the GSA Administrator, the PTA authorizes the Administrator to provide them with services and resources in addition to those that were provided to them as candidates."

CRS: "The President’s FY2020 budget proposal for GSA included a request for $9.62 million in funding for activities authorized by the Pre-Election Presidential Transition Act of 2010 in anticipation of the 2020-2021 presidential transition."

CRS on GSA's actions following Bush-Gore 2000 presidential election: “In this unprecedented,incredibly close & intensely contested election,w/legal action being pursued by both sides,it is not apparent to me who the winner is.That is why I have not ascertained a President-elect.”

Legislation to improve the orderly transfer of executive power during Presidential transitions was signed into law by President Trump in March.Senate passed bill by UC in 2019 & House in Feb on voice vote,following debate managed by then-NC Rep/now WH Chief of Staff Mark Meadows.

Meadows (R-NC) in February 2020 House floor debate on the Presidential Transition Enhancement Act which "addresses a number of ambiguities about how agencies work with Presidential transition teams that were identified by the Trump transition team." https://www.c-span.org/video/?c4923312/house-debate-passage-legislation-amend-presidential-transition-act-1963-improve-orderly-transfer&editTime=1605363600 @cspan