Before you can claim your knowledge panel, you need to be verified by Google as an authorized representative of your organization:
Ensure that you have a Google account and, if not, create a new one
Go to Google Search
Search for yourself or for your organization (the entity you are representing for the knowledge panel)
Scroll to the bottom and click Claim This Knowledge Panel
When you click on the option to “Claim this Knowledge Panel”, you’ll be redirected to Google Search Console. Learn more about claiming your Google Knowledge Panel here.