You can follow these steps to get your Apple push certificate and upload it to your mobile dashboard.
1. Open Keychain Access.
2. Navigate to Keychain Access > Certificate Assistant > Request a Certificate From a Certificate Authority…
3. Fill in the Certificate Information and choose Saved to disk to continue.
4. Click the Save button.
5. Sign in to your Apple Developer Account.
6. Navigate to Certificates, Identifiers & Profiles > Identifiers > Your Identifier.
7. Make sure that the Push Notifications option is enabled.
8. Navigate to Certificates, Identifiers & Profiles > Certificates.
9. Click the + (add) button. 
10. Create a New Certificate and select Apple Push Notification service SSL (Sandbox & Production). Click the Continue button.
11. Choose your App ID and click the Continue button.
12. Choose File and upload your CertificateSigningRequest.certSigningRequest. Click the Continue button.
13. Download your certificate to your Mac. Double-click the aps.cer file to add in Keychain Access.
14. Your certificate should look as follows:
15. Right-click on your certificate and Export it.
16. Click the Save button. You can set a password or leave it empty.
17. Go to Insider Mobile Dashboard and navigate to Settings > Mobile App Settings > Push Notification.
18. Enable iOS Push Notifications via Checkbox.
19. Upload your certificate for production & development environments.
20. Enter requested inputs.
21. After you upload your certificate, it should look like as follows:
22. Choose your current server state.
23. Do not forget to click "Save Changes" at right top of the settings page, otherwise all progress will be lost.
