Graduating with a BSN in March 2024. How can I still apply to RN positions if I don't have my licensure yet but expecting it soon?

The same as you would normally, the only exception is under education in resume/education put “expected to graduate March 2024” would also include gpa.

If you are a strong candidate, you can go through the whole interview process and be set up for a job, however, you won’t get an official job offer until you obtain your license.

Look for hospitals that take interns so you can do an internship program and you can be hired.