1. In your Gnosis Safe Mobile app, open the Settings
2. Open the App Settings
3. Tab "Import owner key". This will guide you through the process to enter the seed phrase of your owner account that you want to use on mobile.
4. Enter your seed phrase
5. Select the account you want to use. (Context: You can derive multiple accounts from a single seed phrase. If you don't know what that is, continue with account #1.)
6. You now have successfully imported your account and are ready to use it for confirming transactions.