Open Chrome and click the three dots in the top right corner

Choose settings from the menu (third from the end)

Select 'Privacy and security' on the left of the settings page (third from the top)

Select 'Site Settings' (Second from the top)

Select 'Notifications' (Sixth from the top)

Under the 'Allow' Section, click the three dots on the site you don't want to send notifications

Select 'Block' from the menu.

Repeat the last two steps for any additional sites and then

Close the settings tab.