disable cache in siteground website
use the following code in .htaccess
//Disable the cache on a non-WordPress website
<IfModule mod_headers.c>
Header set Cache-Control "private"
</IfModule>
//Exclude a single page from the cache
<If "%{THE_REQUEST} =~ m#/sample-page#">
<IfModule mod_headers.c>
Header set Cache-Control "private"
</IfModule>
</If>
//Exclude all files of the same type from the cache
<IfModule mod_headers.c>
<FilesMatch ".(js|css|xml|png|jpg|jpeg|html)$">
Header set Cache-Control "private"
</FilesMatch>
</IfModule>
//Exclude a specific file from the cache
<If "%{REQUEST_URI} =~ /filename.php$/">
<IfModule mod_headers.c>
Header set Cache-Control "private"
</IfModule>
</If>