Hi Chen Zhi,
Sure. here is my share point list.

For ur Q2.
In this case, it should be considered to add a new item, I guess?
Q3
Save the record after filling up the request form in Share Point.
Q4
Ideally, the default status is In progress, and after the line manager and the senior manager approve the request, the status will update to Approved.
My problem now is
1. I've managed to use the default template archive to send the approval to the line manager and the senior manager. Two managers already approved the request but the status still shows In progress. I tried to add Share Point in Power Automater but the flow is failed. Wondering to know how to makes it auto-update the status via Power Automate.
2. How to add send an email to the requester in Power Automate? I tried this way, for some reason, it doesn't work as expected.

Will be grateful for any help you can provide.
Sk73