"£37bn has been allocated to its budget for two years and it spent £22bn of that in the first year."
You're half right.
'How much has Test and Trace cost so far?
£37 billion was budgeted for NHS Test and Trace (sometimes incorrectly referred to as Track and Trace) in its first two years. That amount hasn’t been spent yet.
NHS Test and Trace spent £13.5 billion up to April 2021, and its budget for that year was £22.2 billion.
According to a National Audit Office report on its progress, this £8.7 billion underspend was primarily due to the fact that “the high level of demand for testing forecast for January and February 2021 did not materialise, in part due to national lockdown measures.”
NHS Test and Trace is not just the NHS Covid-19 app. It also covers testing services, ‘contain’ activities’ (including identifying local outbreaks and supporting local responses to the pandemic), and tracing services.'
https://fullfact.org/health/nhs-test-and-trace-cost/