It's important to note initially that, thanks to the many Minecraft Java vs Bedrock differences, this only applies to the Java edition of the game. You can't allocate more RAM in Bedrock.

You can try the following methods to resolve the Minecraft memory error: allocate more RAM or memory to Minecraft by starting the game using the “Java edition or Options” or “Minecraft ...

If you're interested in how to allocate more RAM to Minecraft or your Minecraft server, have a look at our written tutorial.

Go to the Java/Minecraft tab from the new window that opens. The first option, "Maximum Memory/RAM," can be altered by using the two arrows beside it to change the memory allocation (in megabytes).

When one plays Minecraft, the official launcher of the game automatically allocates a certain amount of RAM to a version. Whenever this version opens on a device, the allocated RAM gets occupied.