Anyone know how you earn a Captain Marvel/Darth Vader watch? There are challenges that ask you to use them but not how to get them in the first place?

It is written on the description of those badges:

And of course, you need to have the respective watch physically, in order to be able to add it to your account. You can find them in Garmin's online store here:

• Avengers Smartwatch | Captain Marvel | Garmin
• Star Wars Smartwatch | Darth Vader | Garmin