Invizion

In this case, how to properly split the HTML string to be worked in Gutenberg editor.
I just can’t find a way to properly do it.
How can I automatically and properly format the HTML string with blocks API?

So I guess I made some progress, but got stucked again.

With the code:
wp.data.dispatch('core/editor').editPost({tags: [id]})

Where ID is the post tag ID, it adds the post tag to the input, but I have my tags as text, so I have two problems:

If post tag doesnt exist, create it by text;
Get post tag id by name and add it to post;

I’ve got it.
Added the link to ajax.php as url and it worked. Now I can make my json requests.

For future information in case someone need it:

                $.ajax({
                    type: 'POST',
                    dataType: 'json',
                    url: '/wp-admin/admin-ajax.php',
                    data: {
                        action: 'call_udemygrab',
                        value: url
                    },

Unfortunately, your solution keeps refreshing the page for me.