Hi Has anyone been able to get Salesforce Mobile app to connect to a Sandbox, if so could you give idiot proof instructions I've tries everywhere but I cant get it to work. Thanks James

Hi Thanks to you all for your help, I finally managed to connect the main issue was I didnt have a password app on my phone to store the passkey doh! 

1. Installed Apple Password on phone 

2. In Salesforce Setup > My Domain >

check this 

3. In Salesforce Profile Settings > Advanced User Settings > Built-in Authenicators Add 

4. Go through the steps to crate a passke and make sure you pick the Phone option  

5. Then on the phone I was able to login using the SSO 

James