Dear Sir and Madam

This is Shuji Kamitsuna@Japan.

I am translating the "Payment Request API" published on September 8, 2022.

I noticed some potential typos:
Sec. 3.1, Could "optionally letting" be "optionally informing"? (I'm not sure.)
Sec. 13.4, "If isRetry if false" might be "If isRetry is false".
Sec. 14.8, Is "available. purposes." the correct expression?

Best Regards,