How to add Advenced Custom Fields In Single Post

I Need Help, i add acf code in single post download button showing but in link of download button same of link post, i add other website and link in button download always same, whats wrong in my code or is there something missing so that acf doesn’t work

< div class=”site-wrapper f-width”>
< div class=”container site-content”>
< div class=”wp-block-button is-style-outline”>”>Download Now

        <?php endif; ?>