Did you open up the script editor and paste in the script shown in Tim's tutorial?
Did you save and then publish your script as a web app, with the web app executed as you (your google account, same owner as the sheet), and accessible by anyone (with 'even anonymous' if using the legacy script editor)?
If you did all these things, you should have created the required Google Sheet. Something is wrong. What does your Google Sheet look like? When you display the sheet on your Google Drive, it will look like something like:
Copy the url you see. You should be able to paste it into an new window in your browser and see your sheet. If you post that link to your spreadsheet here in the forum, I will look at it for issues and might be able to help.
Your script is not connecting because you have missed a step in creating the link or you are not using the correct url in your app Blocks. Google provides two links to the spread sheet when you create a script. The correct url needed in the app is the script link; The script url will look something like
https://script.google.com/macros/s/AK................... . Be aware, this is different than the https://docs.google.com/spreadsheets... link to the spreadsheet
Try to post the link to your Shared spreadsheet here . Only then someone might be able to help Maslo.