It must be noted that the WeChat public platform is Tencent's business. Don't regard other advertising third-party development companies as WeChat public platforms. Their registration is charged.
If it is an individual application, you can only apply for a subscription number, and you need to provide a clear photo of your ID card.
Companies can apply for subscription number and service number, and need a business license.
If the application is successful, you can log in and get familiar with the interface, but the function can't be used yet. You have to wait for the review, and the review will soon pass. The help document says it will take seven working days, but in fact two or three days have passed. The success of the audit can be seen in the mail sign in the upper right corner.