Is there a limit you can send to Apple Pay

See the following from Apple Cash and person to person payments limits - Apple Support

Sending or receiving limits

• Per message, you can send or receive a minimum of $1.
• Per message, you can send or receive up to $10,000.
• Within a 7-day period, you can send or receive a maximum of $10,000.

You might also be limited by the available balance on your debit or prepaid card or limits from your bank or card issuer.

Are you talking about Apple Cash or are you talking about making a payment to a store through Apple Pay? Apple Cash and person to person payments limits - Apple Support

How to avoid scams when using Apple Pay to send and receive money - Apple Support