Reorder subtask button in top operations bar

Hello everyone,
I would like to move the button to create subtasks to the first position of the operations bar, I have seen in the following link: How to re-order the list of issue operation in an issue | Jira | Atlassian Documentation, that it is possible to modify the order of these buttons, however, I have tried to modify it several times and I can not get it as I want, could you help me with this matter?