The Xiaomi Mi Smart TV 4A already has the corresponding functions to be used as a "wireless display". In addition, you can install further apps with which it should also be possible. However, the decisive factor is your laptop and your operating system.
Under Windows 10, it should be possible in principle. In the end, all that remains is testing. For further research, I recommend the search terms "miracast", "Laptop HP XY miracast" and "dxdiag miracast".

No, you need additional apps such as ApowerMirror on your TV and on your laptop. As usual, these are unfortunately not free and the quality is not exactly a hit!