.htaccess RewriteRule url只有数字[重复]

I would like me site to load php files even if I dont add the .php Example:

domain.com/test

Will load domain.com/test.php I did it with:

RewriteRule ^(.*)$ $1.php

Now I want url with ONLY numbers to be redirected to homepage with the number storing in $_GET['sponsor'] I did it with:

RewriteRule ([0-9]+) index.php?sponsor=$1

So Example: domain.com/888 Will load domain.com/index.php and $_GET['sponsor']=888

The problem is that any url with number give me and error, For example domain.com/vendor/fontawesome-free/webfonts/fa-solid-900.woff

How can I change the htaccess so ONLY numbers will be redirected, any other real file with number in his filename will keep loading as is ?

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