To not misgender a student, you have to be using their correct pronouns, but I don't know if there is any way to do that without other students knowing that you are not using their AAB pronouns. If the student doesn't mind everyone knowing their pronouns, you can always lead by example and gently correct any other student.

While introducing themselves during the first day of school, you could have students state their pronouns along with their name. This would ensure each student is addressing their pronouns, so the transgender student won't feel objectified and as if they are the center of attention.

I would ask the students to make it a whole class question; everyone should say what they want their gender or pronouns should be so they won’t be singled out.

If a student is being misgendered in class purposefully, I would identify the student doing it and bring them to admin.

I would let the students know that they need to respect pronouns and gently correct them whenever they are wrong.