GPS application

How come the road is not visible when I press navigation, although I have formulated that it should be visible. I work like the tutural on YouTube "Maps-Markers an More - MIT App Inventor Hackathon 2020

Welcome Elke.

I do not know. Perhaps you did not provide an ORS API key? Show your Blocks and or an aia Elke.

or you might try:

Are these all of your Blocks? Not enough.

You need a LineString to draw the route and an api key to be allowed to use the Navigate service.
Navigation

Perhaps these blocks will help

vvSimpleNavigateBlocks

Do they?