You can request cards from your teammates. Any Silver card can be requested.

Here's how:

➡️ In the main Collections screen, tap on one of the sets and choose a card from the set that you don't have yet.
➡️ Tap on the desired card and then tap Request. Please note that the Request button is only available for Silver cards.
➡️ Your request will appear in the team chat, and if one of your teammates has a duplicate of the card you want, they will be able to share it with you.

Please note:

• Since Gold cards are not exchangeable, you can't request such cards.
• In the team chat, only players who have a duplicate of the card will see your request.
• You can request only 1 card within one day.
• If you aren't part of a team yet, check this article on how to join a team.