A total of 1 review of this product on Reddit.
28th Dec 2020
>With Duolingo I can just tap on the umlaut vowels and double S, but it’s not a great solution and won’t be present if I’m typing on other websites/applications
A physical keyboard doesn’t make any difference, you need to install and switch to the appropriate layout in your settings.
You could use the US international layout and type Umlauts like this or install the German one and buy some keyboard stickers.