So I had this working about a year ago using James Montemagno helpful how to site but as the years have gone by the code has changed, I have managed to get this working on the android side changing the code to what Google now wants but not being very successful on the IOS side and wondered if anyone who has managed to get this working if they would mind sharing there code, please
I have the following in AppDeligate
MobileAds.SharedInstance.Start(completionHandler: null);
and my key in info
but sadly my AdInterstitial class is such a mess I dread pasting it here and wonder if anyone can help. I have tried marctron.admod for ios
but sadly this didn't work for me either
Thanks for your input LandLu but the link you provided had some dead links within it and might be the reason I didn't end up using it. but currently have managed to mash something together so for android which is working 100% I used this link
https://www.c-sharpcorner.com/article/google-admob-display-ads-in-xamarin-forms/
Which said it did both Android and IOS but the IOS wasn't showing the ads but might have worked if I gave it more time but then found this video on line and this does seem to work occasional for IOS and so that will do for me
Answers
Have you tried this approach:
https://stackoverflow.com/a/56702220/8354952
We need to instantiate an admob on the iOS side and then present it on the Forms page.
Thanks for your input LandLu but the link you provided had some dead links within it and might be the reason I didn't end up using it. but currently have managed to mash something together so for android which is working 100% I used this link

https://www.c-sharpcorner.com/article/google-admob-display-ads-in-xamarin-forms/
Which said it did both Android and IOS but the IOS wasn't showing the ads but might have worked if I gave it more time but then found this video on line and this does seem to work occasional for IOS and so that will do for me
The only problem with putting your solutions on a forum is 2 weeks later when Xamarin.GooglePlayServices.Ads 119.7 update appears which depreciates your solution you cant help wonder if someone is working against me
Thanks Gerald for putting this issue to rest, I had looked at this in the past but it didn't work but after watching video this fixed all my issues with ease