https://www.psychiatrictimes.com/view/psychopharmacologic-treatment-of-bipolar-ii-depression

"In brief summary, our current recommendations are as follows7,8: after considering electroconvulsive therapy for patients who are severely depressed and are in urgent need of treatment, the first-line medication options are quetiapine, lurasidone, cariprazine, lumateperone (all FDA approved), and the combination of lithium and lamotrigine. Olanzapine/fluoxetine is generally not recommended because of the unacceptable long-term adverse effect risks of the olanzapine component.

If these first-line options fail (some of them may be unsuitable for use, given individual patient considerations), you could try an antidepressant if the patient is not a rapid cycler, does not have a depression with mixed (ie, manic) features, or has no history of mania or dysphoria with previous antidepressant use. If any of these predictors of adverse outcomes with antidepressants are present, try more combinations of the top 5 choices next."