Decided to make a guide as some people might not know how.
First go to playit, create a tunnel, minecraft java, click create tunnel (dont touch the ipv4 and port we will tune that later)
Downloading server jar
Go to https://serverjars.com/ where you can find server jar files . For this demo just download 1.19, click Vanilla and download 1.19. Open in winrar or 7zip. Click META-INF, versions, 1.19 (you can use ‘modded’ version of vanilla server such as papermc)
Making a folder for server jar and playit
Make a folder on your desktop and put the server jar inside, also make a folder for playit. Download 0.9.3 version
Making a bat file to run server
Now you need to make a bat file to run your server. Make a text document (Notepad) in the same folder as your server, paste this in '@ECHO OFF java -Xms3G -Xmx3G -jar forge-1.16.5-36.2.20.jar nogui pause ’ with out the ’ follow according to the picture.
Ignore forge-1.16.5-36.2.20 replace with whatever version you downloaded in this case it will be -jar vanilla-1.19.jar or something similar
[Refer to this section later on] in brackets 
[*Xms is minimum amout of ram used and Xmx is maximum amount of ram used. In this case I have set it to use 3 gigabyte of ram used. *
For optimized settings refer to Aikar’s Flags. I recommend using Aikar’s flags as it will reduce ram usage such as when the server does not need the intended minimum ram of 2gb it will use lesser than that
If you see in your server cmd something like running behind ticks if is above something like 1000 ticks add more ram, it means the server is lagging behind. However you should add more ram when there are multiple reports of your server lagging, other issues can cause this as well such as your wifi or cpu.]
1st time running server
click save as, save file type as all files, name the file run.bat
Now run playit and the run.bat files.
It should prompt you to agree to EULA. Close the cmd, open EULA.txt in your server file set to true and save. Also a good time to check the server properties file to adjust things such as, if you want to disable pvp set pvp to false, change ports and all that. For now dont change anything.
After EULA set to true run your server again. Don’t close playit, playit portforwards your ports so if you dont have playit open if will not work same if you close cmd.
Setting ur local ipv4 ip and port number
Now go back to playit website adjust your tunnel. Set local ip as your ipv4 ip. You can do so by running cmd as admin and type ipconfig find your ip and put in local ip. Default port for minecraft is 25565 however if you want to change this you can but make sure to do so in the server properties file as well called server-port
After that try and connect to your server with both your local ipv4 address and the playit address, it should work.
If you have errors like connection timed out could be due to that you did not set up the tunnels correctly. There are lots of reasons to this such as your wifi and others. If you get this issue ask in the discord as I personally never have this issue.
That’s the end of the guide. Thanks for reading!