Allow apps to use your contact information
Some apps and websites can use your contact information to provide you with services and features. For example, an app might use your contacts to help you address emails or share messages with friends. See Control access to your contacts.
To authorize an app or a website to use information from your contacts, click Allow in the dialog. If you don’t want to authorize the use of your contact information, click Don’t Allow.
If you allow third-party apps or websites to use your contact information, any information they collect is governed by their terms and privacy policies. It’s recommended that you learn about the privacy practices of those parties.
You can review and change which apps and websites can use your contact information in Privacy & Security settings.
Choose Apple menu > System Settings, click Privacy & Security in the sidebar, then click Contacts. (You may need to scroll down.)