You need to list your business on Google My Business for adding the website to it.
Go to www.google.com/business/ and log in using your business ID.
Once logged in, click on the ‘Info’ tab on the left-hand side menu.
In the ‘Info’ section, all your business details will be listed. Scroll down to the ‘Add Website’ option and click on the pencil icon next to it.
In the dialog box that pops up, enter your business website and click on ‘Apply’. Now your website will be linked to your GMB profile and will be visible to searchers online.