To wake up your computer over the network, you need a Wake on LAN app on your phone, laptop, or other device.
Some programs have built-in Wake-on-LAN. For example, TeamViewer has a "wake up" button that you can press to activate a sleeping PC connected to your TeamViewer account. You must check the documentation for your own remote access tool to see if it supports Wake on LAN and what settings you need for the feature.
In other cases, you may need a separate program to wake up your PC. If you're trying to wake up a PC from another Windows computer, I recommend WakeMeOnLan from NirSoft. It will search your network and provide a list of devices so you do not have to remember the IP address every time. Just click on the desired machine and click on the wake-up button.
Depicus is another good tool, although you need to enter the IP address, MAC address, subnet mask and port number for the remote PC more advanced.
If you do not have a PC on hand, you can use a mobile app like Wake On Lan (Android) or Mocha WOL (iOS). They work the same way as the desktop apps mentioned above: You can either browse your network for devices or enter the IP and MAC address of the computer you want to wake up.
If everything is ok, your computer should wake up immediately when you press the Wake Up button. If not, check the BIOS settings, Windows settings, and Wake on LAN app configuration to make sure all settings are correct for your specific hardware.
If you want to quickly enable your computer without scanning every time It is probably a good idea to set a static IP address for your computer on your router so that it does not change.