Update README.md

README.md

@@ -54,9 +54,12 @@ See [Advanced usage](#Advanced-usage) for more options.
 There are two versions of `curl-impersonate` for technical reasons. The **chrome** version is used to impersonate Chrome, Edge and Safari. The **firefox** version is used to impersonate Firefox.
 
 ### Pre-compiled binaries
-Pre-compiled binaries for Linux and macOS (Intel) are available at the [GitHub releases](https://github.com/lwthiker/curl-impersonate/releases) page.
+Pre-compiled binaries for Linux and macOS (Intel) are available at the [GitHub releases](https://github.com/lwthiker/curl-impersonate/releases) page. Before you use them you need to install nss (Firefox's TLS library):
+* Ubuntu - `sudo apt install libnss3`
+* Red Hat/Fedora/CentOS - `yum install nss nss-pem`
+* macOS - `brew install nss`
 
-These binaries are statically compiled with libcurl(-impersonate) for ease of use. If you wish to use libcurl-impersonate, please build from source.
+The pre-compiled binaries are statically compiled with libcurl(-impersonate) for ease of use. If you wish to use libcurl-impersonate, please build from source.
 
 ### Building from source
 See [INSTALL.md](INSTALL.md).