Block anonymous numbers with huawei?

I'm constantly being called anonymously, even at night! I have the huawei p9lite, who knows how I can generally block anonymous contacts?

I also had a long time that I was called again and again. It had not been that extreme for me. But at some point that stopped again.

Could you imagine someone from your environment who wants to harm you that way? Maybe a stalker or something? I could imagine something like that.