I need to make custom entity animation for 1.12.2 (Yes, I use older version of Mcreator)

I saw a geckolib tutorial on forum but it says it only works for 1.15.2 (also couldn't make it because game crashed but this is not important) and I couldn't convert my Mcreator to 1.12.2 with the 1.12.2 plugin so I downloaded older version of Mcreator in order to export it as 1.12.2. Is there any other way to make custom animation for entites for 1.12.2?