在网页浏览器中前往http://www.canyouseeme.org 输入端口号。 点击检查端口。

Given the above summary, write a detailed text in English for it.
You can use it to see if a port on your computer or network is accessible on the internet. The website will automatically detect your IP address and display it in the "Your IP" box. There are many different sites you can use to check for an open port. Search for "open port check tool" in your favorite search engine to find an alternative, if desired. Type the port you want to check (e.g., 22 for SSH) into the "Port to Check" box. If the port is open and available, you'll see a confirmation message. If not, you'll see a message that says "Error: I could not see your service on (your IP address) on port (the port number)."