https://www.cbafaq.com/salarycap.htm#51
When a team signs a first round draft pick within three years after he is drafted, they use the salary scale for the year in which he signs (usually the player signs in the same year he is drafted). After three years they have the option of either using the salary scale or signing him as if he was a free agent -- using their cap room or any available exception, with the standard raises. They can only do the latter if the player did not play intercollegiately in the interim.
Such a contract must be for at least three seasons, and the salary in the first season must be greater than 120% of the applicable rookie scale amount.
I want to say that I got the info about no team/player options in these type of rookie contracts when the Bulls signed Nico Mirotic this past offseason. I was curious as to how the rules applied to Tomic and Neto (and now Pleiss).