Where's the authority for this? None. They stole the land, invaded the country, displaced the government, and now they annex it.
...In 1945, where the Nazi government tried to maintain that some of the annexations of foreign territory that it had undertaken before and during the Second World War were entitled to legal recognition, The Nuremberg Tribunal itself in 1945 said, "No, annexations are invalid, prior to the conclusion of a peace treaty."
The United States government and the President conceded they've engaged in acts of war, they're occupying, they put themselves at war with your people. Now they've annexed it, but the annexation has no validity under international law. If as part of the peace treaty between Hawai'i and the United States you want to concede them some land that's up to you, that's your choice. Or if you want to give them operating facilities for a base upon the payment of funds and rent or something, that's for you to decide, but now they have effectively in this law invalidated the entire annexation. The whole legal basis for it has now been invalidated.
If the annexation of the land is invalid, then where does the title come from, who has title to the land? It's the Native Hawaiian people who retain title to the lands of Hawai'i, as a matter of international law. Not the federal government, not the state government, but the people themselves.