“Oklahoma Bans ‘Quality of Life’ Health-Care Rationing”
(National Review — May 26, 2020)

HB 2585 was a legislative referendum that, if passed by the legislature, would have been submitted to voters for approval in June 2018.  If passed by the voters it would have enacted the “Oklahoma Death with Dignity Act.”  The legislative referendum failed to pass the legislature.
Text of HB 2585

Current law regarding assisted suicide:

A person who willfully furnishes another person with any deadly weapon or poisonous drug, knowing that such person intends to use the weapon or drug in taking his own life is guilty of aiding suicide if the suicide occurs or is guilty of aiding an attempt at suicide if the person attempts to use the weapon or drug to take his own life.

An injunction to prohibit a person from assisting a suicide may be issued and the court may award compensatory and punitive damages to the party requesting the injunction.
Okla. Stat. Title 21, §§ 813-817 and Okla. Stat. 63, §§ 3141.1.

A Joint Resolution (HJR 1009),  ordering a legislative referendum to permit doctor-prescribed suicide was introduced.  The referendum would have permitted the “Oklahoma Death with Dignity Act” to appear on the Oklahoma ballot on June 26, 2018.
It failed to pass.
Text of Joint Resolution

A doctor-prescribed suicide bill (HB 1673), titled the “Oklahoma Death with Dignity Act,” was introduced in Oklahoma. It failed to pass.
Text of bill