Program not working after I changed LED circuit

You have posted your question to an existing thread.
You should have posted a new thread.
Please report/flag your post and kindly ask a moderator to split it off.

You have not posted your code in code tags like advised in the forum how to.
Read again the forum how to how to post code in code tags.

Edit your post and put the code in code tags.

You don't have a solid ground connection.
Try again with a circuit like shown here:
https://docs.arduino.cc/built-in-examples/digital/BlinkWithoutDelay/