1. How to block unwanted calls
With newer versions of Android, it's becoming easier to block unwanted phone calls on your phone. The simplest and fastest method is:

Open the Phone app
Enter the "Call Log" or "Recent Calls" menu
Select the number or unwanted contact and hold down
Click on "Block number" in the menu that has just been displayed. You can do this same manipulation to unlock a number
Note: For Xiaomi and Huawei phones, it is necessary to first create a contact card with the unwanted number to block it.

To unblock a number that no longer appears in the log or view your blacklist:

Open the Phone app
Open the menu with the three dots and go to the settings
Select Calls> All Calls> Auto Reject List
2. How to record a phone conversation
There is no internal Android functionality for recording phone conversations. However, if call recording applications are available on the Play Store, it is possible that most of them no longer work with the arrival of Android Pie, Google has chosen to restrict the development of this type of application. application for legal reasons in some countries.

The only known exception is MIUI overlay Xiaomi manufacturer, where it is possible to activate call recording in the settings.

Another tip for recording a call on Android is to:

to download a dictaphone application on Android,
start recording before the call,
put the call into speakerphone.
3. How to listen to YouTube in the background
To listen to YouTube in the background on your smartphone:

Open your Chrome browser on your phone
Enter the YouTube URL in the search bar (do not visit the app!)
On YouTube, click on the small dots at the top of the window and select "Computer version"
Start your music, minimize the window. If the music pauses after the window is minimized, click the play button in the notification banner.