I have my Apple ID password, but I have forgotten the answer to the security question, what should I do?

Hello!

Change your Apple ID security questions - Apple Support

If you’ve forgotten the answers to your Apple ID security questions – Apple Support (AU)

After you’ve reset your security questions, you may want to set up two-factor authentication instead. It's the best way to keep your account secure, and you won't need to remember any security questions. You can set up two-factor authentication straight from your iPhone, iPad or iPod touch with iOS 9 or later or your Mac with OS X El Capitan or later.