The Kasa app has widgets. There's no need to get IFTTT involved. Also, check out the community integration for Kasa, it works way better than IFTTT.
For you to use Teamviewer's WOL function, you need to make sure that WOL is enabled in your computer's BIOS (usually under Boot) and in your network adapter's settings. Setting those up is going to vary depending on manufacturer, model, and OS. Google is your friend.
If you are using a Wi-Fi adapter, WOL will only work if you have a WoWLAN (Wake on Wireless LAN) capable laptop and you use sleep mode instead of hibernate or off. Also the laptop must be on AC power when being put into sleep mode.
