Snort 3.1.47 Configuration Issue on CentOS 8.5: undefined variable name: RULE_PATH - configuration

Question

I'm working to install snort 3.1.47 on CentOS 8.5 while following the "Snort 3.1.00 on CentOS 8 Stream" manual from Snort's official documentation.
I finished configuring snort along with this manual and I'm now trying to start Snort on my network interface using the following command.
/usr/local/snort/bin/snort -c /usr/local/snort/etc/snort/snort.lua -i enp37s0 -l /var/log/snort --plugin-path /usr/local/snort/extra -k none
However, the output this command generates mentions the error FATAL: ips.rules:2 undefined variable name: RULE_PATH while reading my snort.lua file.
The content of the ips array inside my snort.lua file is as follows:
ips =
{
mode = tap,
rules = [[
include $RULE_PATH/snort3-app-detect.rules
include $RULE_PATH/snort3-browser-chrome.rules
include $RULE_PATH/snort3-browser-firefox.rules
...
include $RULE_PATH/snort3-x11.rules
]]
}
The RULE_PATH variable is defined in the snort_defaults.lua file:
---------------------------------------------------------------------------
-- default paths
---------------------------------------------------------------------------
-- Path to your rules files (this can be a relative path)
RULE_PATH = '../../rules'
BUILTIN_RULE_PATH = '../../builtin_rules'
PLUGIN_RULE_PATH = '../../so_rules'
-- If you are using reputation preprocessor set these
PASS_LIST_PATH = '../../intel'
BLOCK_LIST_PATH = '../../intel'
I don't understand why it would be undefined, because snort_defaults.lua is imported at the beginning of the snort.lua file:
---------------------------------------------------------------------------
-- 2. configure defaults
---------------------------------------------------------------------------
-- HOME_NET and EXTERNAL_NET must be set now
-- setup the network addresses you are protecting
HOME_NET = [[ 192.168.1.0/24 ]]
-- set up the external network addresses.
-- (leave as "any" in most situations)
EXTERNAL_NET = 'any'
-- dofile(conf_dir .. '/snort_defaults.lua')
-- dofile(conf_dir .. '/file_magic.lua')
include 'snort_defaults.lua'
include 'file_magic.lua'
What could be making Snort think that my RULE_PATH variable is undefined?
I have googled to fix this issue, but I could not find the right solution.
Thanks you in advance for your answer.
Regards.