Hi Aimee, thanks for stopping by and dropping a question. Yes I can tell you how you can do that:

• go to Firebase Console
• select the project you want to customise
• on the left hand side tab, go to Authentication
• then, go to Templates tab
• select Email address verification
• click on the pencil icon
• at the bottom, you will find Action URL box and underneath it there’s the customise action URL clickable text
• put in your webpage link to which you want your user to be redirected after clicking on the email verification link

I hope this helps!

Let me know if you have any other questions.