Convert youtube links to embed / iframe

no, that’s not how you’d get a YouTube link. That gives you a link to the current page on your site.

Just paste in the link on a line by itself — something like

https://youtube.com/watch?v=123456

and WP will take it from there.

No i think there is theme problem or just cause i heavily modified the theme.
I got it working before dont remember the link i was visiting it was long time ago.

get_the_permalink() has *nothing to do* with youtube.

This may be a plugin or theme conflict. Please attempt to disable all plugins, and use one of the default (Twenty*) themes. If the problem goes away, enable them one by one to identify the source of your troubles.

If you can install plugins, install “Health Check”: https://www.ads-software.com/plugins/health-check/ On the troubleshooting tab, you can click the button to disable all plugins and change the theme for you, while you’re still logged in, without affecting normal visitors to your site. You can then use its admin bar menu to turn on/off plugins and themes one at a time.

See https://www.wpbeginner.com/plugins/how-to-deactivate-all-plugins-when-not-able-to-access-wp-admin/

It works on other themes. But not on the one im using cause i modified it or something.
There is some code i can paste in functions.php i remember.

But instead of <?php echo get_the_content(); ?> im using <?php echo get_permalink(); ?> to get youtube link.

once again, no, that will not work. get_permalink gets a link to the current post or page on your site. So you need to figure out how you broke this in your theme.

Yes it was a theme problem. Solved now.