Preserve the official instructions, relevant bank correspondence and actual transaction details, including the reference connecting the payment to the application.
Make reconciliation possible
Distinguish a proposed transfer from a completed one and retain the official confirmation available. Do not treat a screenshot of a scheduled transaction as proof that the authorities have received and matched the gift. Three records exist for every transfer and they are created at three different moments by three different parties.
The instruction is what the applicant told the bank to do. The execution advice is what the bank did, and it carries the bank's own reference, the value date, the amount that actually left and the amount that actually arrived. The confirmation is what the receiving process says it received and matched.
Hypothetical example: a screenshot of a scheduled transfer is filed as proof of payment, the transfer is later rejected for a formatting error in the reference field, and nobody notices for weeks because the file looks complete. Ask the bank for the formal advice rather than relying on an app's display, keep the reference exactly as the instructions specify it rather than as the bank's field length prefers it, and hold the three records together for each transaction so that any one of them can be checked against the other two.