Can I use a checking account instead of a debit card for Apple Pay?

If you mean Apple Cash, no. Apple Cash must be funded by a debit card.

Hello.

The answer is yes. Here’s from Apple:

You can add a bank account to make Apple Card payments, or use Apple Cash to help pay off your Apple Card balance. The first time you choose to add a bank account, you're asked if you want to add the same bank account that you use with Apple Cash. If you select Yes, the bank account is automatically added.

Here’s a couple articles from Apple that might help: Add or remove a bank account for online Apple Card payments - Apple Support

The quote above is from this article: How to make Apple Card payments - Apple Support

Here is some other thoughts:

you can use a checking account with Apple Pay by linking it to a compatible debit card associated with your account. Keep in mind that the actual transaction might be processed through the linked debit card, but the funds come from your checking account.

Hope this helps.

You can only add credit, debit and prepaid debit cards to Apple Pay in Apple Wallet.

Are you trying to add your checking account to Apple Wallet for use with Apple Pay or what exactly are you trying to do?

Can I use my checking account for Apple Pay my card was stolen and I have to wait 10 days for a new one