In System Settings, Security and Privacy, and Authentication, you can find the options you can choose when adding.

Authentication mode. Among them,

1 "Allow anyone"

After he finds you, he can add you as a friend with one click, recommend people who want to make friends, and choose QQ number for work.

The "question to be verified" is that he will tell you a word, and you can choose whether to add him or not according to his purpose of adding you.

In this way, as long as you set a question and answer it correctly, you can be added as a friend. In this case, usually acquaintances can add success.

In this way, you set a few questions for him to answer, and then you think you can add him, and he can only add you as a friend with your permission.

The last one is "no one is allowed to be friends", which is mainly used because I don't want to be harassed. But it will also prevent acquaintances from adding. Please select your appropriate verification method.