Whatsapp Manager option is not showing in facebook business manager. I am Working on whatsapp business api integration

Question

I am working on whatsapp business api integration. I need certificate to do registration. I Followed the steps mentioned in the documents, added whatsapp account in facebook business manager but "Whatsapp manager" option is not showing. It is supposed to be like this gif: https://files.helpdocs.io/bctwm4322q/articles/u76nm7l1mc/1637669423221/11-business-manager-1.gif

any solution for this?