Originally noted by @jsnmoon. **Steps to reproduce the issue** 1. Attempt to purchase a Search plan via `/purchase-product/jetpack_search/monthly`. 2. Choose a site, then try and press Enter to submit the form. **What I expected** Enter submits the form. **What happened instead** You can use Enter to select a site, but you can't use it to submit the form. <img width="581" alt="Screen Shot 2021-07-07 at 15 53 31" src="https://user-images.githubusercontent.com/17325/124697771-7f7e9a00-df3b-11eb-9b34-afd648e6c1f5.png">