Ok, you made me check further into this.
The Portsmouth Invitational Tournament, (PIT), is the only postseason camp restricted to college basketball seniors. The four-day tournament format consists of twelve games (eight teams of eight players each play three games). 64 players are invited. This year, it started April 17. Joel Soriano made the all-tournament team. The last Portsmouth Invitational player drafted in the 1st round was Derrick white in 2017.
The NBA G League Camp starts May 11 in Chicago. 45 prospects are invited. A select number of players from the draft-eligible group will be invited to participate in the 2024 NBA Draft Combine later in the week based on their performance in the NBA G League Elite Camp. So, those players are in addition to the 78 already invited to the combine. Here is a list:
Armstrong, Mark (Villanova)
Armstrong, Taran (California Baptist/Cairns)
Bal, Adama (Santa Clara)
Brooks, Jr., Keion (Washington)
Burden, Terrell (Kennesaw State)
Carlson, Branden (Utah)
Clayton Jr., Walter (Florida)
Crawford, Isaiah (Louisiana Tech)
Cui, Yongxi (Guangzhou (China))
Daniels, Clarence (New Hampshire)
Darlan, Thierry (G League Ignite)
Dual, Garwey (Providence)
East II, Sean (Missouri)
Edwards, Jesse (West Virginia)
Ellis, Boogie (USC)
Enaruna, Tristan (Cleveland State)
Estrada, Aaron (Alabama)
Flanigan, Allen (Mississippi)
Freeman, Enrique (Akron)
Hinson, Blake (Pittsburgh)
House, Jaelen (New Mexico)
Jones, Isaac (Washington State)
Kaluma, Arthur (Kansas State)
Lanier, Chaz (North Florida)
LeDee, Jaedon (San Diego State)
Lee, Xaivian (Princeton)
Lewis, Jalen (Overtime Elite)
Lewis, Malique (Mexico City Capitanes)
Love, Caleb (Arizona)
Miller, Baba (Florida State)
Miller, Emanuel (TCU)
Mintz, Judah (Syracuse)
Murrell, Matthew (Mississippi)
Ndongo, Baye (Georgia Tech)
Nelson Jr., Jameer (TCU)
Onyenso, Ugonna (Kentucky)
Poplar, Wooga (Miami (FL))
Pullin, Zyon (Florida)
Rubstavicius, Mantas (New Zealand (Australia))
Sane, Babacar (G League Ignite)
Stevens, Isaiah (Colorado State)
Stevenson, Jarin (Alabama)
Tomlin, Nae'Qwan (Memphis)
Warren, Bryson (Sioux Falls Skyforce)
Watson, Anton (Gonzaga)