Ok so I am abel to turn on the theme sandbox or copy it and make it my own.
What file do I have to add to update css? I know there are views but I'm not too familair with the files and its structure.

Thanks.

You can use My plugin is a skeleton plugin to start create your own custom plugin.

Learn about the plugin's structure.

Learn how to make your UI translatable into many different languages.

Learn how to customize the look and feel of Elgg.

Some examples to cteate your custom view or route.

Deep dive to custom plugin's example.

Gotcha! Thanks a lot.

composer.json is required since Elgg 4.

You can play with My plugin which already includes all the necessary files to start coding

Do you have sizes configured for your ' open_graph_image'?

check out https://learn.elgg.org/en/stable/guides/events-list.html#other and then the 'entity:<icon_type>:sizes, <entity_type>' event

Thanks ... it works now with configured 'open_graph_image' sizes

Elgg Docs.

Examples: 1, 2, 3, etc

Just check out the plugins.

Or clarify your question

In first, you must to activate 'Log level' option on the  'Debugging and Logging' section in 'Site Settings' page.

I recommend 'Log errors and warnings' choice.

Now you can activate 'Elgg Developer Tools' plugin and switch on 'Enable error log' option.

Now you'll able to see 'Error log' there.

The best way is regular checking the server logs.