Problems connecting online from phone (Joiplay)

I have been trying to connect online from Joiplay but I am struggling to figure out how. I was told to rewrite net script but I can’t seem to find it on my phone. Is there any easy guide on here on how to do that or how to connect online through Joiplay? I have the complete version of 1.2.7 downloaded. Also, would I risk my save file doing this? Thank you for any answers, I am new to all these things.