Nginx Rtmp and FFMpeg | is it possible to make variable for ffmpeg settings?

I try to do variable for ffmpeg settings but always giving error! is it possible to add one variable for all different output

i set variable like this

set $ffmpegsettings "-c:a aac -ac 2 -ab 128k -ar 48000 -c:v libx264 -x264opts 'keyint=24:min-keyint=24:no-scenecut' -b:v 1200k -maxrate 1200k -bufsize 1000k -vf 'scale=-2:720' -f"

and use it at exec_static like this

exec_static ffmpeg -i http://myiptvlink $ffmpegsettings flv rtmp://localhost:1911/output/tv1;

exec_static ffmpeg -i http://myiptvlink $ffmpegsettings flv rtmp://localhost:1911/output/tv2;

exec_static ffmpeg -i http://myiptvlink $ffmpegsettings flv rtmp://localhost:1911/output/tv3;

exec_static ffmpeg -i http://myiptvlink $ffmpegsettings flv rtmp://localhost:1911/output/tv4;

i test nginx with configtest its “ok” but not creating hls. how to fix it?