oppo f1s second sim not displaying. help needed

[Android Central Question]

Hi All, I have an oppo f1s. I recently got a second sim , so I can have a second number. The second sim will not show up on the phone.
When I touch on "mobile networks" only 1 sim displays on screen. I have watched a few youtube clips where both sims are dsplayed, unlike mine. Any help to resolve this would be appreciated. Thanks, Tony

 

[B. Diddy]

Welcome to Android Central! These steps don't work? https://www.helpforsmartphone.com/public/en/oppo/f1s/android-5-1/guides/22/Set-up-Internet-OPPO-F1s