Yes but no. Modern PHP lets you put types in function signatures and it will then attempt to convert your inputs to those types at runtime.
JS/TS and Python don’t do this. They have optional type annotations that’s treated as syntactic sugar. You can use static checkers against this but if you get an error like “expected string got int” you can still run the code. It won’t behave any differently because you have annotations.
When I went rooting around to find it. I figured it was some QA process that starts 5 seconds after the video loads (the timer seems to be async and the code sends a promise off while it waits). Of course, it’s all minified JS so it’s a huge pain to read.