How do I move my aircraft into a newly created fleet?

If anyone could help, I am very confused on how to move my aircraft into a fleet that I have created?

Thank you!

Top menu bar, Operations -> Fleet Management,

check the aircraft checkbox, and on the bottom select a fleet under "Fleet assignment" and click Execute.

Top menu bar, Operations -> Fleet Management,

check the aircraft checkbox, and on the bottom select a fleet under "Fleet assignment" and click Execute.

Thank You!