I love Xdrip, but it does indeed expect one be a little tech savvy.
The build-your-owm-Dexcom app, though, is a complete misnomer. You don’t have to actually make anything. No tech skills required at all. All you do is answer a quick questionnaire, and they email you the install file. You just click the link in your email. Your phone will probably pop up a warning saying it doesn’t have permission to install the file from your email app, since it’s not the Play Store, but give you a link to follow to grant the permission. After doing so, click the emailed link a second time, and this time the install will run, and you’re in business. The app will work identically to your previous experience with it, no matter the phone or Android version.
The hardest part is simply choosing the right version for you from the possibilities. If you’re in the US, you want “G6 US v1.10.0.6 (Android 9+)”. If you’re outside of the US, then you want the “G6 International v1.10.0.2 (Android 9+)”
On the second page of the questionnaire, you have to click the first box about removing the comparability check. That’s the entire point here. The others, you can just pick the default option. I would highly recommend you choose “yes”, instead, on the question asking: “Do you want swiping/dismissing a notification to take the same action as pressing OK?” Choosing “yes” here will allow you to quickly stop an alert by just swiping it away in the main notification bar, rather than having to open the app and clear the notification there.