Do I need to recompile Apache 2 with apxs for PayPal?

[Frappy John]

I'm trying to install and configure PayPal Website Payments Pro using
the PayPal PHP SDK.

The first step in the SDK Quickstart instructions is:
Enable Apache modules and APXS (Apache Extension Tool)
In your Apache root directory, run:
./configure ?enable-mod=so --with-apxs /usr/local/apache/bin/apxs (sic)

I think of the  ./configure directive as a precursor to compiling with
"make," yet there is no mention made of running "make".

I'm running RHEL 4.1 with Apache 2 precompiled. I can see that modules
are enabled, but I'm guessing it wasn't compiled with apxs since I
just installed apxs 10 minutes ago. (FWIW, it's part of the
httpd-devel package.)

But, then, when I search the Apache site, I see no mention of a
"--with-apxs" directive for Apache 2 (only for Apache 1.3). So I'm
thinking the instructions may be a little off. Is there such a
directive for Apache 2?

So I'm wondering if this step is really necessary. I hate to futz with
a perfectly fine Red Hat installation if it isn't.

Does anyone know how PayPal uses apxs? Does it actually build its own
module to be loaded into apache? If I proceed without recompiling
Apache, how will I be able to tell if my existing installation of
Apache is inadequate?

Any help would be appreciated. Thanks.