First up, Terms of Service - https://www.fiverr.com/terms_of_service
Josh’s answer is correct, but needs fleshing out just a touch for Voice Over people.
There are two additional ‘licenses’, which can/should be purchased for Voice Overs, all dependent on the end-use of said voice over. You can charge what you like for these. Simply put, the two are;
Commercial Usage - Applicable if the end recording is going to be used to sell something. (ie; your voice is going on an explainer video, that’s going to sit on a company website, advertising a product).
Broadcast Usage - Used to simply mean “if going on TV or Radio”, but thanks to the changing landscape of advertising, we now explain this as ‘if the voiceover is to be used as part of any advertising campaign, online or offline’.
The subtle difference between Commercial and Broadcast is whether it’s for a paid ad campaign. So it could be the same video that I mentioned in the Commercial Usage example, is then going to be used as part of a paid ad campaign on TV. Or Facebook Ads, or Instagram Ads, or LinkedIn ads etc. In this case, Broadcast Rights must also be purchased, IN ADDITION TO Commercial Usage.
(The only situation where Broadcast Rights would apply, but Commercial Usage wouldn’t, might be a charity video that’s being used as part of a paid advertising campaign, for example, as the recording technically isn’t selling a product or service, for commercial gain).
Typically, VO people charge less for Commercial Usage (as it’s very common), and more for Broadcast. You can choose what you like, but it might be a good idea to see what other VO people in your field are charging, and stay close to that.
In terms of how the buyer receives the licenses, so long as they are included when purchasing, my understanding is that the ‘proof of purchase’ is their proof of having the necessary licenses, and they can then refer to the Terms of Service if they would like more info about said licenses. We’ve sold a huge volume of licenses in our time on Fiverr, and we’ve never had a client ask for an actual document.
It’s not as slick as dealing directly with a VO agency - but then, the average Broadcast Right on Fiverr is $50, versus potentially several thousand dollars via an agency, so it kind of makes sense.
Hope this helps.