Using Composer 1 despite showing Composer 2

I’m trying to add an extension on a shared server. When I look at the version of Composer at the root level for Magento 2.3.5, it tells me 2.0.8.

When I view the free memory, it appears that I have more than 1G.

The command I am running is: PHP -d memory_limit=-1 bin/magento

After it tells me that it’s installing, I get a message that Version 1 is being used and then after loading composer repositories, I get a message that Composer 1 has been deprecated.

Shortly thereafter, it aborts on a mmap failed (12) cannot allocate memory.

The support for the extension says that I should be using Composer 2 which has a smaller footprint. However, I don’t know how to do that.

Thanks in advance,

Jeff