Add troubleshooting for invalid client id error (#6244)

* Add troubleshooting for invalid client id error

* Update authentication.markdown

* Add a note to remote document

* ✏️ Spelling and grammar tweaks

source/_docs/authentication.markdown

@@ -50,6 +50,24 @@ While you should hopefully be storing your passwords in a password manager, if y
 
 When you start Home Assistant next you'll be required to set up authentication again.
 
+### {% linkable_title Error: invalid client id or redirect url%}
+
+<img src='/images/docs/authentication/error-invalid-client-id.png' alt='Screenshot of Error: invalid client id or redirect url'>
+
+You have to use a domain name, not IP address to remote access Home Assistant; otherwise you will get **Error: invalid client id or redirect url** error on the login form. However, you can use the IP address to access Home Assistant in your home network.
+
+It because we only allow using IP address as client ID when your IP address is one of internal network address (e.g., 192.168.0.1) or loopback address (e.g., 127.0.0.1).
+
+If you don't have a valid domain name for your Home Assistant instance, you can modify the `hosts` file on your computer to fake one. For example, if you are on Windows, edit `C:\Windows\System32\Drivers\etc\hosts` file with administrator privilege, add following entry.
+
+```text
+12.34.56.78 hassbian.home
+```
+
+(Please replace `12.34.56.78` with your Home Assistant's public IP address)
+
+It will allow you to open Home Assistant instance by access `http://hassbian.home:8123/`
+
 ### {% linkable_title Stuck on Loading data %}
 
 Some advert blocking software, such as Wipr, also blocks web sockets. If you're stuck on the Loading data screen, try disabling your ad blocker.

source/_docs/configuration/remote.markdown

@@ -15,6 +15,10 @@ If you're interested in logging in to Home Assistant while away, you'll have to
 Remember to follow the [securing checklist](/docs/configuration/securing/) before doing this.
 </p>
 
+<p class='note'>
+Home Assistant no longer support remote access via IP address since release 0.77, you have to use domain name.
+</p>
+
 The most common approach is to set up port forwarding (for any port) from your router to port 8123 on the computer that is hosting Home Assistant. General instructions on how to do this can be found by searching `<router model> port forwarding instructions`. You can use any free port on your router and forward that to port 8123.
 
 A problem with making a port accessible is that some Internet Service Providers only offer dynamic IPs. This can cause you to lose access to Home Assistant while away. You can solve this by using a free Dynamic DNS service like [DuckDNS](https://www.duckdns.org/).