Please see below to link an external link to a button on your website steps:
Go to Website > Edit website.
Click the button you want to add/change the URL to.
In the Button settings tab, select "External" from the link list and paste the external link. (Please remove the #)
- You may choose the "Open link in a new page" option if necessary.
Change the Label, and add the website URL.
Click "Save" in the top bar.