Chase may not provide statements through Third Party Access. If statements don't arrive, connect with the account owner's login.
If your client uses Chase and gave you a read-only accountant login, your client can turn on Third Party Access for that login. You can then use it to connect Chase to LedgerSync through MasterCard. The article "Third Party Access Chase Bank" shows the steps.
A connection saves you from downloading and uploading statements by hand, and it gives you more:
LedgerSync only reads bank data, such as statements and transactions. It has no feature that moves money.
When your client connects Chase through MasterCard or MX, they sign in and approve access on Chase's own page.