If the event organizer has enabled this, you can go to your profile settings and pick one of the available alternatives, such as Zoom or Skype. After you have chosen another video conferencing platform, a new field will appear in which you can add your personal Zoom link, or Skype username.
Please be aware that if you are using a free Zoom account, the link MUST have a password included for it to work (if there is a ‘pwd=’ in your URL, you’re good).