Do NOT use these methods in these videos above! It will fail.
Maybe that worked for older version, but not with version OBS 30.
Go to the YouTube video entitled, “How To Create Obs Lower Thirds For Your Video Content In 2023”. USE that method for install and setup!
You will discover the correct “Properties for Lower Third” (Browser) is something like this: file:///C:/Program%20Files/obs-studio/Animated-Lower-Thirds_1.6/Animated-Lower-Thirds/lower%20thirds/browser-source.html
Now the Circle around the lower third box will turn BLUE! NOTE that you had this type of string: "file:///etc..... Otherwise it will not work!
It will now work!