The Server Jar and the forge give us an error

OS Name/Version: Windows

Product Name/Version: 10

Problem Description:
good afternoon, I have a problem within Hostinger in which I get an error alert every time I want to put the Forge to play with mods. When I have to select the type of server and I indicate forge, after putting the forge version in java it does not let me start the server, but if I put a vanilla version there is no problem.
Currently we try to play in version 1.12.2 and when it takes us the java it does it by installing 1.19

The error says: Unable to start server. The minecraft server stopped within 5 sec of starting(…) you should check you minecraft servers log files to find out why it is unable to start

Actions taken to resolve so far:
We tried changing the type of version of Minecraft when creating the server and it only gives us more errors.

Clarification: I’m sorry if there is consistency in what is written, English is not my language

Please post the log files. If you can access ADS through a browser, right click the trouble instance and View Logs. Otherwise, you can find your log file in the AMP_Logs directory in your instances datastore. Please be aware that the name of the license holder is contained within the log.

Luckily we were able to solve the problem by changing java to its version 8. But the server now has an error that even if it is forge and we put mods on it, it is vanilla because after waiting for the mods to be downloaded within the server now we don’t know They come into the game and when we put an object in creative of the mods we are expelled.