The "Backup-Real" time does not work. Separate from the need to change from real-time to a scheduled backup plan, deleting your backups immediately is risky and not recommended. The first issue you may run into is accidental deletion. if a file is accidentally deleted and your backup runs, it will detect the deletion and if your retention settings force an immediate deletion of the backup file, then your data cannot be restored. The other example would be something like a ransomware attack. Files are often renamed by the malware with the originals deleted, and again, if your backup runs then all the ransomware encrypted files are saved in backup storage but your original files are deleted.
It's best to delay the deletion for some period; whether that's a couple days or more. It's also a good idea to keep multiple versions (at least two) of each file. That will protect you against a file change (on purpose, accidental, or malicious) and then finding your only backup copy is the newly change, but bad one.