To be able to support our setup, your ISP router needs to have a dedicated public IP address assigned by your Internet Service Provider, which can be either static or dynamic.
Method 1:
Ask your Internet Service Provider directly whether you have a public IP address at home or not. If not, kindly request them to have it changed into a public one. Once they have changed it you are good to go.
Method 2:
Check it quickly by yourself. Please follow the steps bellow:
STEP 1: Find out your home router's WAN IP address
You will need to connect to your home router and find out which IP address is assigned to it by your ISP.
STEP 2: Find your IP address on the Internet
Go to https://whatismyipaddress.com and find out your IP address online.
STEP 3: Compare your router's WAN IP (from step 1) with your IP address on the Internet (from step 2)
Compare the IPs collected in steps 1 and 2. If they are the same, you are good to go. If they are different, you will need to request a public IP from your ISP.
Please refer to this document and below video guidelines for more details.