This is a "one-time" message from Apple. Clicking on the "Learn More..." button will take you to the Apple website which explains that this is a 32-bit application and, in the future, 32-bit applications will no longer be supported. Clicking on the "OK" button will acknowledge the message, and it will not appear again. Here is the link:
https://support.apple.com/en-us/HT208436
CaptureOnTouch will function as normal (even after this message appears). Canon is working the solution that will prevent the need for this message occurring in the future.