How do I change my phone number on Instagram if I’m locked out

I have been locked out of my Instagram because they think someone is trying to hack into my account. So now I need to verify my account but the verification code they sent was to my old number. so there’s no way for me to get the code. Every time I go onto the app, it automatically goes to “YOUR ACCOUNT HAS BEEN TEMPORARILY LOCKED” and my only option is to verify. But to verify I need to change my number and cant do that if I cant go to the main page.