WordPress tutorial: How to install WordPress 5.8 RC beta? | 2021
Learn WordPress: You can install the latest WordPress version 5.8 before the actual release using a simple plugin. However, please note that this is the beta version thus do not update to your running live site or client’s site instead on the sites you do not use.
With WordPress 5.8 you can use it to test the plugins or themes you are using and as well as explore functionality of the newest WordPress before the actual release. This WordPress version 5.8 RC is not a hack rather only a beta version. It is estimated that the official download will be released on 20th July and is expected to bring lots of site editing features making it easy to work with websites.