Hi
When receiving money via Apple Pay Cash, funds may be available immediately, but account security checks might require additional time.
Funds are credited to your Apple Pay Cash Card balance and are only transferred to your bank account if you subsequently choose to do so.
More information and instructions are available via the Apple Support articles linked below.
If you still need help, then I suggest contacting Apple via the link at the bottom of the first article.
More information:
Send, receive, and request money with Apple Pay - Apple Support
Transfer money from Apple Pay Cash to your bank account - Apple Support