Installation
Step 1: Download all the required files
Step 2 : Install Java
Step 3 : Install Launcher
Specify the version of Java and amount of memory to use

You will need at least 4GB of memory.
For MacOS, if you used the Java link above, you can use:
/Library/Java/JavaVirtualMachines/amazon-corretto-17.jdk/Contents/Home/bin/java
Step 4 : Install the Modpack