The 2020 Presidential Preference Primary ballot requirements are yet to be posted.
But we think that
Similar to Connecticut, Maryland, Mississippi, Nebraska, New Mexico, North Carolina, Tennessee and Wisconsin
The Secretary of Sate determines which candidates appear on the presidential primary ballot. Also, a presidential candidate can petition for placement on the primary ballot.
It is a closed Primary, which means you must be registered to vote as “affiliated” with whichever party's Primary you wish to vote in.
The Primary is on May 19, 2020