Power Automate - Teams & Planner. Create message automation for different Planner boards with internal and external people.

I have tried to create a power automate flow that is:

Trigger- 'When a task is assigned to me'

Action - 'Post a message in a chat or channel.

The problem- I want a different message to be sent based on the Planner board (i.e 2 task boards in Planner, one for Team A and another for Team B). When a task is assigned in Task Planner 1 for a member in Team A- I want a message sent to the assignee stating 'Youve been a assigned a task (maybe specify the task board name and the task name). Click here (hyperlink to Task Planner 1) to see.' I need this automation to work with a team internally and externally to the company (they will be added to a teams channel for Team A/B).

Problem 2- the flow has also failed internally as it could not recognise an employees email which differs slightly in their email domain as there are multiple parts to the company. As team members will all have different domains how do I work around this.

Then I want a separate automation for Task Planner board 2 for Team B. and the 'Click here (hyperlink).' to take the Team B member to the right task Planner board.

I also want to creat other automation that work in the same manner for when a task is completed, created etc.

Additionally, I was wondering if there was a way to create a automation that once a task is completed and now the next person in the sequence can begin their task (as the next task relies on the completion of the prior task), a message can be sent to notify the next person that the person responsible for the previous task has completed it and now they must complete their task.

Ideally it would be great to have an automation when a person assigns a task, a message is sent to the assignee that says 'Hi. I've just assigned you (task name) in (planner board name). Click here to see (hyperlink to task or board).'

The aim is to reduce emails when collaborating with an external company and streamline the process. We want to essentially be like 'we have completed our part, now its your turn' and when they have completed their task, we can move on to the next task too. Where everyone can see which task is next in the project and how far the project is from completion to reduce a back and forth and ensure a smoother way to stay on top the projects. Also to send prompts on only Teams to let internal and external members of the team know they have a task to work on.

Is power automate able to achieve this or is there another software that integrates with Teams/Planner or would a power automate pro license resolve this issue? I have very little IT/developer/coding skills but power automate seems relatively easy. Would there be support from Microsoft to create these flows with a Pro License?