Question

I want to create a ToDo database and then from other pages say e.g. @todo-database which adds an entry to that links back to the specific spot where I added the todo

Answer 1

You could a button to do so, I suppose. Buttons are now allowed and linked with database automations.

Answer 2

So, you can do this with a Button but it's a multi-step process and requires that your Button is in something like a sync'd nav block that shows up on every Page.

Button

When Button is clicked:

1. Add page to todo-database
2. Open New page added in Side peek

Then when you click the Button, the new todo-database entry will open where you can give it a Title and any other Property value needed.

Let's say you Titled the DB entry "Test Entry 1"

Close the Side Peek and you'll still be in the Page where you clicked the Button.
Now just type @Test Entry 1 (Notion will give you "Pages" to choose from) and this will create a link directly to the new DB entry.

And if you view the DB Entry Detail for "Test Entry 1 you'll see it has a "Backlink" to the Page where you created the link to the DB Entry.

Hope this makes sense.