You can run free and ticketed shows on Bandcamp. There are benefits to each:
Free shows give you the best chance of bringing in as many fans as possible, as they will only need a free Bandcamp fan account to attend the show. If you're promoting an upcoming release or doing a more impromptu performance, free may be the way to go. The more fans you can bring to your show, the more eyes you'll have on your merch table. We also allow fans to support you directly during the show with a "Show your support" button, as well as a smorgasbord of simulacra that fans can purchase for you during the show. So even though entry is fee, free shows are a great way for fans to show you their support.
If you decide to charge for your show, don’t be modest when it comes to setting your price. You have most likely put just as much work into this as an in-person gig, and it is a unique opportunity for your fans to connect with and support you. Think how much attending a regular live show costs and work from there: a $10/£10/€10 ticket should be reasonable. If you want to sweeten the deal, you can always include a digital release in the price of admission. You can do this via the "Options" tab in the live stream editor.