Cannot access the button inside the mail from

I am trying to click the button “Verify Email” inside the mail. As you can see in the screen shot, the button exists inside the “a” tag. But I cannot access anything by using xpath inside the mail. I also used the “Spy Web” feature from Katalon and it doesn’t work. Is that becasue of the or need something to be able to click the button.

Second image is the object from the Spy Web.
If you know the solution for that kind of problems, please help me.
Thank you in advance.