nginx image filter -> [emerg] unknown directive "image_filter_webp_quality", "image_filter_interlace", "image_filter_output"

I compiled nginx with image filter module, but when including directives listed here

http://nginx.org/en/docs/http/ngx_http_image_filter_module.html

I gest errors when testing

nginx: [emerg] unknown directive "image_filter_webp_quality" in /usr/local/nginx/conf/conf.d/www.it.conf:245
nginx: [emerg] unknown directive "image_filter_output" in /usr/local/nginx/conf/conf.d/www.it.conf:246
nginx: [emerg] unknown directive "image_filter_interlace" in /usr/local/nginx/conf/conf.d/www.it.conf:45
nginx: configuration file /usr/local/nginx/conf/nginx.conf test failed

obviously the compilation make give me that webp is supported in gd

checking for GD library ... found
checking for GD WebP support ... found