You do not need to delete and should not delete your existing API as this will result in the existing data being deleted. CryptoTaxCalculator has an update API feature that allows you to add updated APIs for the same exchange/account. When your imported API has expired, you can follow the below steps:
Generate a new API by following the instructions on the Import page.
Click three dots and select ‘Update’.
Copy and paste the new key.
After syncing successfully, you should see the below data on the Transactions page:
The existing data imported via the old API until the date it stopped working.
The newly imported data via the new API is from the date you updated the credentials.