diff --git a/README.md b/README.md
index b65c998..21ed6c2 100644
--- a/README.md
+++ b/README.md
@@ -99,6 +99,11 @@ Note that while mobile is checked for functionality, the web experience is not m
 
 If you are getting errors about preflight checks, it's probably CORS related. Make sure your UI sits on the same subdomain as headscale or inject CORS headers.
 
+### Errors related to "Missing Bearer Prefix"
+Your API key is either not saved. Create an API key in `headscale` (via command line) with `headscale apikeys create` or `docker exec <headscale container> headscale apikeys create` and save it in `settings`.
+
+Alternatively, you haven't fixed your domain. HS-UI *has* to be ran on the same subdomain or you need to configure CORS. Yes you need to use a reverse proxy to do this. Use a reverse proxy.
+
 ## Development
 see [development](/documentation/development.md) for details