Send an email reminder when a task in Project for the Web is approaching its due date

Many thanks for all the kind help. Appreciated. I have started playing around with the alterations and slowly I will find a way. My first try ended up sending all the "test" tasks to all the company emails (I guess something wrong in the loop). Is there any way to test those flows in a test environment and avoid such issues? As I said in my initial email I want to build a flow that:

1. Runs once every week
2. Checks all the projects for all the tasks that are due in the next month
3. Check all the projects for all the tasks that are already late
4. Collects the respective assignees
5. Sends an email to each of the assignees with his due and late tasks
6. The same email goes to the Project Manager

Hence I am struggling to create a loop that can separate the above information per assignee and send the respective email.

I don't know if there are other internet sources where you can find customized templates that could probably address the above or if I have to use a service provider to do that (in case my tests fail).