Hi Alexandru,
You need a single relation to update current user row. You can create a Template column on your Things Table and then fill the template column clicking the three dots with User Profile>Email column.
And then add a relation column and select the the template column you created and select Users table > email. And don’t tick the multiple checkbox. It needs to be Single.
And in your form add the Increasement action and select the single relation and select the number column that created in the Users collection for the column.
Thank you