There are several options for purchasing an eSIM card in the USA. Here are some of the most common options:

Online eSIM marketplaces: You can purchase an eSIM card from online marketplaces such as esimcard.com ,eSIM.net, eSIMs.com, or Airalo.com. These marketplaces offer eSIMs from a variety of carriers and can be purchased and downloaded online.

Carrier websites: Many carriers, such as AT&T, T-Mobile, and Verizon, offer eSIMs for purchase on their websites. You can visit their websites to see if they offer eSIMs for your device and purchase them online.

Mobile app stores: Some eSIM providers have mobile apps that you can download and use to purchase and activate eSIMs. For example, the GigSky app can be downloaded from the App Store or Google Play and used to purchase eSIMs.

In-store purchase: Some carrier retail stores and electronics retailers may also offer eSIM cards for purchase. You can check with your local store to see if they carry eSIM cards.

When purchasing an eSIM card, be sure to check that it's compatible with your device and that it offers the coverage and features you need. Additionally, make sure you understand the activation process and any associated fees before making your purchase.