If you own a smart TV that uses the Roku streaming box technology, and your TV is connected to a home wireless Internet Service Provider, why don't you simply go into your TV, go the main Roku screen.
On the lefthand menu options, scroll down until you see Channels, click on Channels and do a search for YouTube channel/app.
Download the YouTube channel/app to your TV.
Launch the YouTube app on your TV.
Login, using your YouTube user account info, into the YouTube app on your TV.
You can, now, view YouTube directly on your TCL flat screen TV using Roku.
In addition, if you use the YouTube app on your iPad, using the same home wireless Internet network, you should be able to use the YouTube app, on your iPad, to link/mirror your videos, wirelessly, by, first, starting a YouTube video from your iPad.
In the upper right hand corner of the video, tap a small rectangular icon
When you tap that rectangular icon, if all devices are on the same wireless, WiFi network, your TCL Roku TV should appear in a drop down menu.
Tap your TCL TV and the YouTube video that was playing on your iPad will now play in YouTube app/channel on your TCL Roku TV.
Another option.
Roku streaming technology supports Apple AirPlay 2.
So you can just AirPlay your entire iPad to your TCL Roku TV
If all devices are on the same wirless, WiFi network, on your iPad slide a finger downward from the upper right hand corner of your iPad to reveal the iPadOS Control Centre.
Tap the overlapping rectangles icon ( screen mirroring icon ) a dark gray pop-up should appear listing a panel with your TCL Roku TV.
Tap your TV panel.
Apple AirPlay should load and install and launch on your TV.
A 4 digit code will appear on your TV and at the same time a code input window should pop-up in the middle of your iPad.
Type the code into the box on your iPad to activate AirPlay link to both devices.
Then you could do whatever you want to do on your iPad and it will be mirror’ed to your TCL Roku TV.
To exit out of Airplay when you are done using your iPad this way, swipe a finger downward from the upper right hand corner to, again, reveal the iPadOS Control Centre.
Tap the overlapping rectangular icon ( screen mirror’ing ) again and tap the Stop Mirror’ing Panel.
Best of Luck to You!