Why are you getting confused unnecessarily ?
For spend based fee waiver, your spends would be counted from issuance date, unless specified otherwise.
Bill will generate as per Billing cycle.
If card was issued on 20th March 2023 then for fee waiver , spends of 20th March 2023 to 20th March 2024 would be considered, unless specified otherwise.
Note:
Always do some extra spends over and above that is required for Fee waiver.