Hey, i have installed the Wake-on-LAN binding but it doesn’t show up in the things tab to be able to add a device.
The Network binding includes wake-on-lan capability. Is this what you mean? In that case it is a Network thing that you need to add.
Things and UI configuration were only added in OH2. Because the WoL Binding is an OH1 Binding, you can only use and configure it using textual configuration.
how can i do that, i tried but it doesn’t work
You add a Switch item like in the examples to an .items file in conf/items:
Switch WoL_Computer "WoL Computer" { wol="192.168.1.255#00:1f:d0:93:f8:b7" }
Make sure to update the broadcast IP (192.168.1.255) and MAC address (00:1f:d0:93:f8:b7) so it matches your network and computer.
Then you add a Switch item to a .sitemap file in conf/sitemaps:
Switch item=WoL_Computer label="WoL Computer" mappings=[ON="WoL"]
After that you can press the button on the sitemap to start the computer in Basic/Classic UI or one of the mobile phone Apps. 
i have done that but the pc doesn’t turn on
Did you also check if you can switch on the computer using some other WoL magic packet sender program? If that also doesn’t work, you might first need to enable WoL in the BIOS of that computer.
ok, thanks
You have posts in other threads that show you are working on OH3. OH3 simply does not support old V1 bindings.
For OH3, you need to install the network binding and then you can easily add a netowrk thing and configure WoL through the UI.
Can’t find the feature on the network binding.
The Binding’s docs have got you covered there:
It’s a setting on a pingdevice thing. So create the thing and set the mac address. But note, this doesn’t show up as a channel for the thing once you create it. The WoL capability is an action so you will have to trigger it via a rule. If you want to have that connected to a switch item, then you need to create a proxy switch, and a rule that is triggered by that switch.