When I scan the QR for my receive address in another app, I see an error message.

If you attempt to scan the QR code for one of your Samourai wallet's receive addresses via a third-party service and see an error message, then the service you are using may not yet support bech32/Native Segwit addresses yet. 

As of update 0.99.81 to Samourai,  bech32 addresses are now the default address type used by the wallet. If you require  another address type, they are still available via the advanced options on the Receive screen.

To change your receive address type to Segwit Compatibility or Legacy, simply tap the gearbox/settings icon at the bottom of the Receive screen in Samourai, and adjust your address type accordingly.