This is currently an experimental feature available on Safe Mobile (iOS only).
Active the feature
To activate this feature, first navigate to Settings > Experimential and activate the switch for Enable WalletConnect for keys.
Connect external signer key
After you activated the feature, you can add external signer keys by navigating to Settings > Owner keys and click the "+" button in the top-right. You can choose to either connect with one of the suggested wallets from the list (currently only Metamask Mobile) or connect any wallet that supports WalletConnect (a second device might be required to do so). After you have connected the external signer key, it will be displayed in your list of keys.
Use external signer key
Signing with an external key works similar to traditional signing with an on-device key. The only difference is, that when you select the external key, you will be forwarded to the external wallet (Metamask, etc.) to finalize the signing process. After you signed the transaction there, you can return back to Safe Mobile.
