Sadly,
Cred is not available in the US App Store .
To use UPI, the bank operating the account needs to support OTPs to non Indian numbers for UPI transactions. AFAICT, SBI only supports OTP to international numbers for their bank transactions (that too with the occasional unexplained outages) and not for UPI.
Anecdotally, I’ve heard ICICI does support that. I’m toying with idea of exiting SBI for ICICI for this (and other) reason