diff --git a/electrum/plugins/trustedcoin/trustedcoin.py b/electrum/plugins/trustedcoin/trustedcoin.py
index bd62c123d..c1b3a510f 100644
--- a/electrum/plugins/trustedcoin/trustedcoin.py
+++ b/electrum/plugins/trustedcoin/trustedcoin.py
@@ -465,6 +465,9 @@ class TrustedCoinPlugin(BasePlugin):
             self.prompt_user_for_otp(wallet, tx, on_success, on_failure)
         return wrapper
 
+    def prompt_user_for_otp(self, wallet, tx, on_success, on_failure) -> None:
+        raise NotImplementedError()
+
     @hook
     def get_tx_extra_fee(self, wallet, tx: Transaction):
         if type(wallet) != Wallet_2fa: