Check out my new code

Question

I hope you like this
https://code.sololearn.com/WlW57a9K772a/?ref=app

Answer 1

doesn't work mate

Answer 2

it says uncaught error line 4

Answer 3

what device do you use?

Answer 4

android 6.0
says uncaught error line 4
when I enter my name it briefly flashes a blue button but then its gone

Answer 5

working fine