Useragent is a browser identifier string that is passed to the server when visiting the website. The identifier contains information about the browser type, the type of browser system and the browser version. Useragent's example: Mozilla / 5.0 (Windows NT 10.0; Win64; x64) AppleWebKit / 537.36 (KHTML, like Gecko) Chrome / 89.0.4389.90 Safari / 537.36
Useragent is used by social networks when composing a device fingerprint. Therefore, various browsers with the functionality of changing the device fingerprint override this value for each new tab. If your purchased account has the Useragent, you should use it to reduce the likelihood of your account to be blocked. The setting procedure may differ depending on the software you are going to use, but as a rule, the Useragent value is simply copied into the program settings field with the same name.
You can get examples of Useragents for different browsers versions and systems using the chrome browser add-on, User-Agent Switcher and Manager. Important, changing the Useragent value is only the part of the work to ensure the secure use of the accounts. It cannot be considered as a complete device fingerprint change, which must be applied for each account separately.