Video doorbells: a tower job and a villa job are different trades
In a villa, a video doorbell is mostly a power-and-signal problem. The natural position is the gate or the boundary wall, which is often the worst wifi spot on the property and may have no power nearby. A battery model avoids the wiring but adds a recurring chore of recharging every few weeks in summer heat that also shortens battery life. A wired unit is the better long-term answer, but if there is no existing bell wiring to the gate, cabling and a wifi extender push a simple AED 250–400 job toward AED 500–800.
In a tower, the problem is permission, not power. The corridor outside your apartment is common area, and a camera pointing into it films your neighbours. Many owners associations and building managements restrict or ban corridor-facing cameras; others allow them if the field of view is angled tightly at your own door. Ask building management in writing before buying anything. Where cameras are refused, a smart peephole camera that replaces the existing viewer from inside the door is usually acceptable, since it captures the same view a resident is already entitled to.