Starting with iOS 18.2, you can set DialLink as your default app for making phone calls. When DialLink is set as the default, tapping a phone number in contacts, messages, or on a website will automatically place the call through the DialLink app.
How to enable it
Make sure your iPhone is updated to iOS 18.2 or later.
Go to Settings > Apps > Default Apps.
Select Calling and choose DialLink from the list.
You can also optionally set DialLink as the default app for sending messages by adjusting the Messaging option in Default Apps.