.htaccess - how to create redirects in apache2 htaccess basing on status code -

i know how create redirects in htaccess status codes except errors (404,503,etc.) , serve specific file test.txt

this trying not work. @ moment trying 503 status code

rewriteengine on

rewritecond %{request_filename} !-f rewritecond %{request_filename} !-d rewritecond %{request_uri} !^/(favicon\.ico|apple-touch-icon.*\.png)$ [nc] rewriterule (.+) index.php?p=$1 [qsa,l]  redirect 503 /test.txt ??? errordocument 503 /test.txt ???