The Oklahoma Election Board web page has this running tally for presidential primary filings. The letters “M” and “T” besides each name indicates whether the candidate filed Monday or Tuesday. Filing ends on Wednesday, December 4.
Three parties are entitled to a presidential primary, but probably no candidate will file in the Libertarian presidential primary. Oklahoma has never held a minor party presidential primary before; in the past, when the Libertarian Party did successfully petition in Oklahoma, it didn’t finish the petition drive early enough to qualify for a presidential primary. But for 2020, for the first time ever, the party was already ballot-qualified and didn’t need a petition.
A Libertarian would have needed either a fee of $5,000, or a petition, which would have required signatures of twenty registered Libertarians in U.S. House district one, twelve in district two, nineteen in district three, twenty-one in district four, and twenty-three in district five. The total would be 95. This sounds easy, but it takes advance organization and it does not appear that anyone seeking the nomination did that work.