Sign in with Apple can give SimFuse a private relay email instead of your personal address. Purchases made under a different sign-in or receipt email may not appear in the same account automatically.
Check which account you are using
Look at the email in SimFuse Settings and use the same Apple account as before. Check Apple's mail-forwarding settings if messages sent to the relay address do not arrive.
Add a website purchase
In the app's Settings, choose Add a purchase from the website, where available. Enter the email from the receipt and complete its verification. This checks whether an eligible purchase can be linked without signing out of your current account.
If the purchase belongs to another registered account or the option cannot link it, contact support. Do not create more accounts or assume all accounts can be merged.
Installation emails may be delayed, but an eSIM already visible in the app can be opened there. See "My order confirmation email never arrived".