What if there is no ground wire in the entrance line of high-rise residential buildings?

There should be. This is a mandatory specification, which involves the safety of electricity use. Check it carefully. If it is not, it will be installed separately.

If it is a new house, you can find developers and property companies and ask them to install it for you.

If it is an old house, it can also be added, because high-rise buildings have special strong and weak wells, and there are grounding trunk lines in the wells, one of which is not less than 4mm? The copper-core insulated conductor can be led indoors from here. Laying method: try to pass through the pipe for protection. If there is a ceiling in the middle aisle, it can be laid in the ceiling, and if there is no ceiling, it can be laid along the corner of the ceiling. Of course, to do this, we must negotiate with the property management company for permission and ask a professional electrician to install it, because there are many details to pay attention to when installing, so I don't know here.