How to open a Minecraft server?

[MapleMoon]

Hello, I am planning to open a Minecraft server for about 7-8 people and I am considering allocating at least 6 GB of RAM to the server. My computer is good, no issues there, but I have installed Geyser MC and Vault plugins because I have friends who play on mobile devices and I want them to be able to join. However, since Hamachi is not available on mobile, I cannot use Hamachi for this purpose. When I tried using Ngrok, I encountered an error asking me to add a credit card for authentication. I would appreciate your help with this. If there are any alternative programs or solutions, please let me know.