You can easily add your VAT-ID (and Chamber of Commerce number) to your profile by yourself.
Below you can read how to do this.
In the app: go to 'Profile' in the bottom right corner of the screen
In the browser: go to 'Hi [your name]' in the top right corner of the screenGo to 'My profile'
Scroll down to 'Invoice and payment'
Click on 'edit'
Enter your VAT-ID (and Chamber of Commerce number) and click on 'Save'
Your VAT-ID has been added
Once your VAT-ID has been activated by the Tax Authorities, you can immediately proceed on the platform.