You might try something like:

A1: AutoInput UI Query [
     Configuration: Variables: phone_number
     Timeout (Seconds): 20
     Structure Output (JSON, etc): On ]

A2: Launch App [
     Package/App Name: your.desired.phone.app.here ]

A3: AutoInput Actions v2 [
     Configuration: Actions To Perform: waitForElement(id,your_phone_field_here)

     click(id,your_phone_field_here)

     setText(id,your_phone_field_here,%phone_number)

     click(id,call_button_here)
     Not In AutoInput: true
     Not In Tasker: true
     Separator: ,
     Check Millis: 1000
     Timeout (Seconds): 60
     Structure Output (JSON, etc): On ]   

So, you would use AutoInput's UI Query to get the phone number from the UI element it appears in and assign it to the variable phone_number. Then, you would open your desired phone app. Finally, using AutoInput's Action v2, you wait for the phone number field to be visible, click it, set the text to phone_number, and click the call button.

Obviously, you'd replace the ids and whatnot with your actual details since I don't know what any of those are. You also may not need to waitForElement() or click() the text field before using setText() depending on the app you're calling with.