This happens when your country or license is not eligible for approval. Facebook always prioritizes the trust and safety of the community. Crypto is a area of constant change and Facebook will also update the list of eligibility requirements. Therefore, to understand all changes, you should clearly understand and regularly access Facebook's advertising policies on crypto products and services. If you do not agree with the rejection of your application, you should resubmit the application form to request reconsideration. You will then need to provide documentation to support your license or registration application.