How do I allocate more RAM to an app.

aha, I did not think of that.

Your game crashed because it accessed location 3, which caused a segmentation fault:

1. Crashed Thread: 1 MainThrd
3. Exception Type: EXC_BAD_ACCESS (SIGSEGV)
4. Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000003
5. Exception Note: EXC_CORPSE_NOTIFY
7. Termination Signal: Segmentation fault: 11
8. Termination Reason: Namespace SIGNAL, Code 0xb
9. Terminating Process: exc handler [0]

It seems to be using 4.2GB of Virtual memory, and has no memory problem that I could detect. location 3 belongs to the system.

Are you running a so-called anti-virus program? that could cause an unexplained crash to an unusual location "to protect you".

Buy 16gb of Ram (buy it from OWC or Crucial) remove whatever is already fitted and replace it with the 16 you bought.

Under modern version of MacOS, any program should be able to simulate any needed additional RAM on your disk drive, (but it will be dog slow). BUT -- that depends on your Mac having LOTS of additional free space on your Boot drive. How much of that do you have?

I have 439 GB of boot disk memory left out of 750.

That is not memory - it is your hard drive space. It has nothing at all to do with RAM.

You may have 12 GB of RAM; if so, you installed an 8 and a 4 GB stick. For best performance, you should match the RAM modules: 2 x 8 GB.

I am getting a bit confused though: I checked for the system requirements for this game and it claims to require Windows.

ARK: Survival Evolved system requirements | Can I Run ARK: Survival Evolved

And, you may want to read this with the recommendations:

How much RAM do i need to run this game? :: ARK: Survival Evolved General Discussions

That's fine; I'd still suggest that you install 2 x 8 GB RAM and check your RAM usage in Activity Monitor. FWIW, the link you posted does not help as it appears to read the user's computer clicking on it - not yours.

You will need to take that up with the vendor of the software or Steam.

This is not a system deficiency -- only that one Application crashed, and it does not appear to be due to lack of memory, it tried to read/write a system address.

this is what I see when viewing the link you posted:

You don't, the OS does, so buy more RAM and fit it, the OS will allocate as much as the game needs (assuming you have enough)

No idea what that measns

1 How much RAM does the game need

2 How much RAM does your Mac have

3 Which Mac do you have

Answer all 3 please

No, answer the questions please.

You just told me that you have 4GB and the Game needs 12GB, so you do not have enough, extra or not it is not enough.