What to save
A WordPress site includes files and a database. Email, DNS configuration and server settings may need separate backups. Explicitly agree what the backup service includes.
Retention and access
A copy stored in the same account can be affected by the same incident. Organise independent copies, protect access and set retention according to your needs.
Test recovery
Periodically restore to a separate environment and check data, files and functions. Record the time taken and steps required. A documented test is more useful than assuming an archive is complete.