Options page for default images settings

Hello,

I was searching for a long time how to set the default image alignment, size & link when inserting an image in a post.

It seems this can be achieved through modifications in the “options page” : https://writenowdesign.com/blog/wordpress/wordpress-how-to/change-wordpress-default-image-alignment-link-type/

This didn’t work for me, as for the only comment of the linked article.

Do someone know why the modification of these options doesn’t produce a result ? Or how to set the default inserted image options ?

Many thanks for your help.