Goto Admin > Ced Marketplace > PayPal Marketplace > Configuration.

Enabled: Set to Yes to enable PayPal Marketplace Payment Method
Title: Set the payment gateway label at checkout
Sandbox Mode: Set to Yes to enable payment method in sandbox mode
BN Code: Enter BN Code of your PayPal partner associated account
Client ID: Enter your OAuth2.0 client ID of the PayPal Rest API app
Client Secret: Enter your secret credentials of the PayPal Rest API app
Partner Account ID: Enter Account ID of the PayPal Partner Account
Enable Admin Business Account: Set to Yes if you sell your own products in this store.
>Admin Business Email ID: Enter the email id of your seller’s PayPal account.
>Admin Business Account ID: Enter the PayPal Account ID of your seller account.
Disbursement Mode: Select the mode of vendor payouts. Select the INSTANT option to automatically disburse vendor amount at the time of order placement. Select DELAYED to disburse the amount manually or automatically after 28 days.
Instructions: Set instructions to display at checkout
Sort Order: Set the order of payment option at checkout