Ios app building fails

building the app fails for ios, no clue why. here is a link:

https://ios.thunkable.com/copy/5af4af35b6d094000165c22a

What is the error and where does it occur?

Something went wrong when we tried to build your app.
Here are the details:

there is a problem building the app - step 2.

I checked everything and it all looked fine.

Hmmm, now it works. I didn’t make any changes. Thanks for your help!

Ok,

I also installed this application - it works.