How to get the difference between 2 Values within a timerange

2024-02-16 01:00:00

0.101

2024-02-16 02:00:00

0.199

2024-02-16 03:00:00

0.200

2024-02-16 04:00:00

0.200

2024-02-16 05:00:00

0.300

This is my table. I want to have the difference between last 2 Values. But only if time is 1h. How do i get this?

If there a null values and the difference cannot be calculated i want to have null as output