Symptom

In the Explorer or Helium App, you get the message that the Hotspot is relayed and you should expect lower earnings.

Cause

In general, your hotspot will still work fine in most cases, even if it is relayed. In some cases, it can have lower performance than expected.

These are the general causes that cause the relayed error:

You have not forwarded port 44158 (TCP) on your internet router
You have forwarded port 44158 (TCP) on your internet router, but you are using 3G/4G/LTE internet and your provider doesn't support port forwarding
You have not correctly set up port forwarding on your internet router

Set up port forwarding for port 44158 (TCP) on your internet router. As every router model is different, this depends on your internet router and we cannot help you here. But, your internet router manufacturer can help. Try to find the manual of it or contact your provider or manufacturer directly to help you out. Sometimes, port forwarding is also called "NAT forwarding" or "Virtual Server" in the internet router settings.
If you have 3G/4G/LTE internet: contact your provider and ask him if port forwarding is possible. If not, you can setup a VPN on your router and allow port forwarding from there. You will need to do your own research on how to do this, as there are thousands of different VPN providers and internet router models (some support a VPN, some not). Start with a Google search on "VPN with port forwarding" and "[router model name] set up VPN" to get started.