In order to control whether or not a "Buy Tickets" link / icon appears next to your gig listings, you must first include or exclude a purchasing link in your booking.
Starting from your Dashboard, go into the Booking Overview for one of your upcoming bookings.
Scroll down to the Itinerary section and click on Add Tickets.
A drop-down card will appear with several fields in which you can enter information about the tickets for that gig like ticket price, sales and notes. In this case, we're mostly interested in the LINK TO TICKET SALES field.
Simply enter the URL of the website on which you're selling tickets for the show. And if it's already sold out, click the SOLD OUT button at the bottom right of the section.
Now click Update Booking at the bottom of the page, and the link will be saved in the overview.
To see the result of adding a link, simply go to your drop-down menu and select ARTISTS.
Find the profile of the artist for whose gig you just added a ticket sales link, and open the PUBLIC WEBPAGES / CALENDAR FEEDS card. Then click on the Open in new tab button for the PUBLIC GIG WEBSITE option.
This action displays the PUBLIC GIG WEBSITE where you can now see the Buy Tickets clickable icon has appeared next to the gig.
If you would like to exclude the Buy Tickets icon, simply leave the LINK TO TICKET SALES field empty when adding information to a particular booking.
The show listings and icons, when displayed on a website as an embedded gig widget, will appear in the same manner as above.