How do you get to Minecraft launch options?

1. Click "Installations"
2. Hover over a Profle line and click on the 3 dots "…" next to "Play"
3. Click on "Edit"
4. Click on "More Options"
5. Edit the setting for JVM arguments, altering the maximum memory argument -Xmx, e.g. to allow 4Gb change that value to read:

Jul 1, 2019