Momentary switch - press once needs to give 5 seconds of power
There are 2 approaches possible here:

You grab a bunch of capacitors, resistors and transistors and start messing around to make a timer circuit. This is the most fun (according to the users of this board) and the most educational, but it is also the most likely to fail. This solution is also super cheap, if you don't value your time much.

You grab an off the shelf component that has solved this issue thousands of times in the field. I personally like the Omron H3DK series timer relays. They are robust and intuitive to use.