You click the button on the left labelled "Click the Button on the Right"

(I know it actually wasn't that way on your phone, but that's your fault for not playing on PC)

Instantly you realize,
"Oh wait, he meant the right button on the actual webpage. Not an imaginary one within the story.
What a terrible way to describe that!"

 

But it's too late.

 

Deep cracks appear on the ground beneath you.
Lava spews forth from chasms as meteors rain down from the sky.

And yet you feel justified in your choice since the old man's instructions truly were abysmal.

"This one's on him,"  you say as the apocalypse consumes the world around you.

What a dumb puzzle.