Have a read of it yourself. PoFA 9(5) states:
The relevant period for the purposes of sub-paragraph (4) is the period of 14 days beginning with the day after that on which the specified period of parking ended.
Sub paragraph (4) states:
The notice must be given by—
(a) handing it to the keeper, or leaving it at a current address for service for the keeper, within the relevant period; or
(b) sending it by post to a current address for service for the keeper so that it is delivered to that address within the relevant period.
So, look at the dates on the NtK you have shown us. The date of the alleged contravention is 1st April 2024. The date that the notice was issued is 3rd May 2024.
If they wish to rely on PoFA to hold you, the keeper liable and they do not know the identity of the driver (they don't unless you blabbed it to them), then the NtK must have been received by the keeper no later than 1st April plus 14 days. They must allow 2 working days from the date of the NtK for it to have been deemed delivered. So, the date of the NtK should not have been any later than 12th April 2024.
The date on the NtK is 3rd May 2024. So, the NtK was not received in time for it to comply with the strict requirements of PoFA 9(5).
https://www.legislation.gov.uk/ukpga/2012/9/schedule/4/enacted