Hi @duc to manh and welcome to the Community!
If your project is company managed, notifications are triggered by events you can find in the project's notification scheme (you can find this from Project settings > Notifications).
You should see a notification event called issue reopened, that you can use for this specific scenario. But, when you design a workflow, a workflow transition by default raises a generic event. If you want to consider a transition as a "reopen" transition, you should look at the post functions of that transition in the workflow and change it from generic to issue reopened. After that, the proper notification will be raised.
On a side note, as - unfortunately - more and more workflows by default use global transitions (where you can transition an issue into any status and back to any other status), this things may not work out. The same transition to In Progress would then only be a reopen if it is used from a done status, but there's no way Jira can determine this in a post function. In that case, you can use an automation rule instead, where you can define an issue transitioned trigger that both names the source and edit status.
If it was my Jira instance, I would go for a well defined workflow with clear transitions between statuses, an issue reopened event on the post function of the correct transition and the proper notifications in the notification scheme.
And lastly, if your project is team managed, the notification settings have fewer options. There is no such thing there as a generic or issue reopened event. So in that case, you may have to opt into the automation rule option.
Hope this helps!
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