1.) Go to the Thank You (Viewing) section on the top.
2.) Scroll down and click "Add/ Edit Bonus Actions"
3.) You'll get a page where you can see/manage all of your bonus actions. At the top of this page, click "New Action"
4.) Here, you can select from pre-made bonus actions or if you want to create your own you can as well.
5.) Fill out the information how you like it and then click "Save & Finish"