"stock reservation" is not a question. I have edited your post to make the title a question.
In the future, please consider using a Question that can make it clear what you ask without requiring people to open your post, as this will often increase the chances people will respond and make everything clearer for others looking for the same answer.
With many subjects posted, not everyone wants to open a post to find out what the question is.
See also https://www.odoo.com/forum/help-1/meta-why-do-some-questions-get-answers-and-others-do-not-25620