I am able to log POST data correctly with the following code:

location /bk {
if ($request_method != POST) {
return 405;
}
proxy_pass $scheme://127.0.0.1:$server_port/dummy;
log_format my_tracking $request_body;
access_log /mnt/logs/nginx/my.access.log my_tracking;
}
location /dummy { set $test 0; }

but the requester gets a 404 return code. I'd like to return a 200 but when I make the following change:

location /bk {
if ($request_method != POST) {
return 405;
}
proxy_pass $scheme://127.0.0.1:$server_port/dummy;
log_format my_tracking $request_body;
access_log /mnt/logs/nginx/my.access.log my_tracking;
return 200;
}
location /dummy { set $test 0; }

The logs are recording blank data. Any ideas on record the data with returning a 200?